Talk:DNA replication

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edit·history·watch·refresh Stock post message.svg To-do list for DNA replication:

There are no active tasks for this page
    • add references/sources
    • add some structure/subheadings
    • clarification and translation into plainer English
    • cleanup of eukaryotic DNA replication section
    • include rolling circle replication in prokaryotic section
    • include information on origin of replication and DNA polymerases
    • include information on viral DNA replication
    • disambiguate for automated DNA (oligonucleotide) synthesis
    • add information relating to D-loop DNA replication of mitochondria
    • mention the purpose of cellular checkpoints in maintaining the integrity of DNA during S-phase (briefly while pointing out to a specific article later)
    • discuss similiarties between eukaryotic and archeal (and archeal - prokaryotic) DNA replication (evolutionary perspective)

    In vitro or automated DNA Synthesis[edit]

    Perhaps a section about how DNA is synthesized in the laboratory?

    DNA can be synthesized in vitro in the laboratory by thermocyclic or isothermal reactions, these methods are called DNA amplification technologies, mainly include:

    [1] Thermocycling reactions

    (1) PCR: Polymerase Chain Reaction, Science,1985

    (2) LCR: Ligase Chain Reaction, PNAS,1991

    (3) PEAR: Polymerase-Endonuclease Amplification Reaction, PLoS One, 2010

    [2] Isothermal reactions

    (1) SDA: Strand Displacement Amplification, PNAS,1992

    (2) RCA: Rolling circle amplification, Nature Genetics,1998

    (3) LAMP: loop-mediated isothermal amplification, NAR, 2000

    (4) HDA: helicase-dependent amplification, EMBO reports, 2004

    (5) EXPAR: Exponential amplification reaction, PNAS, 2003


    --Xiaolong7292 (talk) 01:21, 24 August 2011 (UTC)

    recently edited[edit]

    I have deleted eukaryotic and prokaryotic replication and put it on its separate pages. There is too many specific differences in theses two topics and I will try to fix the entire page, and organize it better. 03/06/07


    shaon== I think there should also be another section discuss the similiarties between eukaryotic and archeal (and archeal - prokaryotic) DNA replication. This is important because it deals with evolution and the relatedness between eukaryotes and archea.see it,,

    The Picture[edit]

    Shouldn't "ozaki fragments" in the picture (png) be "okazaki fragments"?

    rolling circle rep include also

    Easy to break, even easier to fix?[edit]

    For those of you who know a little more about the licencing factors, how about an explanation of why gene shearing is an accepted technology - do we really know what control mechanisms are involved here ? Or is the inherent capacity of the cell to allow for our meddling, increasingly a source of wonder?

    More info?[edit]

    I looked at this page while doing some homework for my high school biotechnology class and found that it was missing a lot of key information. For example:

    -DNA-B first marks the initiation site for Rep (aka Helicase) to begin "cutting" the DNA -DNA Gyrase relaxes the supercoiling so that the section of DNA that needs to be replicated is stretched out -topoisomorase (not sure on spelling) breaks covelant bonds (not sure why, I believe so that Rep has a place to start cutting the strands)

    Also, the DNA polymerase referred to in the picture is DNA Polymerase III, and DNA polymerase I is involved in removing the segments between the Okazaki fragments (because they were created by RNA Primase and use RNA nucleotides).

    I would just edit the article, but this is from notes I took from my teachers lecture and I'm not sure whether or not to submit...


    Topoisomerase and DNA Gyrase are the same enzyme, it just has action in both supercoiling and uncoiling, the fluoroquinolone class of drugs work here actually. Additionally the picture is an extremely simplified representation of DNA synthesis, rather than edit it I would look for a more complete picture that has Pols 1-3 and a description of what they do and in which direction they do it. Most Pols have action in both the 3-5 and 5-3 directions. Pol 1 removes the RNA primers and repairs the region with the last few bases between fragments, ligase is still required for the final 'stitch' between the fragments.

    Etherealmuse 8:05, 17 Feb 2005 (UTC)

    This page also fails to address the obvious question of how the enzymes know how to complete these complex tasks. As it is, we appear to have an obscurium per obscurius, whereby the propensities of celled creatures are explained by a code, but the actions of enzymes remains a mystery. Are enzymes also driven by a code or are they automatically tripped, like thermostats? It is implied by the terminology used if nothing else that decisions are being made by these enzymes. How do enzymes make decisions? If there is a Wiki article that begins to explain this, there should be a link. Neither the enzyme nor the enzyme kinetics article does so.81.164.252.74 00:57, 6 August 2006 (UTC)

    Quick Fix[edit]

    The information about the speed of replication in humans had an error that I cleaned up quickly. It said something to the extent that the an average human chromosome had 6 billion base pairs. This is wrong, the entirety of the human genome has ~6 billion base pairs, which are themselves arranged in 46 linear chromosomes. Average chromosome length is not a particularly good reference as it varries considerably (spanning several orders of magnitude). I cleaned it up to reflect this fact.


    -Mr. Knuffke

    Umm. They don't even span a single order of magnitude - the smallest (21) is 47 megabases and the largest (1) is 245 megabases. Graft 17:30, 8 August 2006 (UTC)

    Why can DNA only be replicated in the 5 - 3 direction?[edit]

    If anyone knows it would probably be worth putting in the article. —Preceding unsigned comment added by 80.42.104.21 (talkcontribs) 22:13, 7 April 2006

    DNA replication proceed in the 5' to 3' direction because the substrates for DNA replication, like RNA polymerization, are 5' nucleoside triphosphates. In DNA replication the 2' deoxynucleoside triphosphates elongate nacent chains in a template-directed fashon by cleavage of pyrophosphate (the terminal two of three phosphate groups) and transesterification of the remaining phosphate to the free 3- hydroxyl group of the growing chain. This increases the chain length by one nucleoside, generates pyrophosphate, and reconstitutes another 3' hydroxly group for continued chain elongation. —Preceding unsigned comment added by 71.128.53.151 (talkcontribs) 15:09, 1 May 2006

    Also: The asymmetery of the promoter sequence —Preceding unsigned comment added by 83.100.173.204 (talkcontribs) 21:24, 16 October 2006

    The reverse sequence 3- to 5- polymerization does occur in nature but would require a different mechanism to dominate the replication process. Prof. Eric Lander (MIT) postulated an explanation of a possible reason natural selection preferred the current order. The reverse process would use contributing molecuels that are more favored for other reactions and thus less available the process. Watch http://ocw.mit.edu/courses/biology/7-012-introduction-to-biology-fall-2004/video-lectures/

    You can not watch more than 10 min of Erics lectures without seeing something that should go in wikipedia. We might be getting a little too technical for wikipedia?? I wouldn't want anyone brain to explode.—Preceding unsigned comment added by Scottprovost (talkcontribs) 20:35, 4 August 2007

    Or you could just look at this picture from Alberts et al. Molecular Biology of the Cell. [1] I'm not watching the video, I don't know which one you're referring to. Proofreading of 3'-5' polymerization would require the energy to add the next nucleotide to be stored within triphosphates on the 5' end of the nascent strand. Proofreading would remove this triphosphate, leaving the polymerase at a dead end. In the 5' to 3' direction energy comes from the nucleotide being added, so proofreading breaking the backbone doesn't remove the energy source.
    I have that figure right here :) ... and that book. To add to the technicality, you could "technically" still polymerize 3'->5' after the proofreading step by activating the 5' phosphate with NAD+ or ATP (similar to how ligase works), but I think nature doesn't want to bother with that. Jimhsu77479 (talk) 08:50, 25 February 2009 (UTC)
    I maintain that the article needs to be cleaned up. I think that this question is, in a sense, a demonstration of problems in the current article being too "technical" rather than focusing on general mechanisms. Madeleine 00:05, 5 August 2007 (UTC)

    Prokaryotes and Eukaryotes[edit]

    In my opinion there should be to separate articles for DNA replication in prokaryotes and DNA replication in eukaryotes. At least it should be made clear if prokaryotic DNA replication or eukaryotic is described. I think I know these two processes quite well, but people who read this to learn about DNA transcription will be unnecessarily confused by unclear parts in this article.

    Additionally I think the different eukaryotic polymerases should be mentioned. They are very essential! I suggest copying some of the information from the wikipedia article DNA polymerases.

    --Happy Puppy 01:38, 2 August 2006 (UTC)

    Too Complicated![edit]

    I'm a Year 12 biology student, and I had heaps of trouble understanding much of this page. --218.215.130.252 10:36, 20 August 2006 (UTC)

    New link to pic and agreement[edit]

    I am suggesting that we add a picture found on the main DNA page, but not found here. The pic to be added to theis page is found here: http://en.wikipedia.org/wiki/Image:Dna-split.png

    I do not know how to add pics, so please can either someone tell me, or post a link to where i can learn how to myself on my talk page.

    Just a quick note - I agree with 218.215.130.252, It is a bit complicated, so a SIMPLE summary section would be nice. I am doing DNA as part of my GCSEs in the UK.

    Thanks

    Stwalkerster 21:23, 16 September 2006 (UTC)

    Expert[edit]

    I may have failed the DNA unit in Biology, but when I was working on an assignment I got confused. Is this DNA replication or protein synthesis?

    --Falconus|Talk 00:43, 10 October 2006 (UTC)

    It is DNA Replication, although this can sometimes be called "DNA Synthesis" as in the new daughter strands are being synthesised. Protein synthesis involves transcription and translation (I can never remember the diff) and the various RNAs. (t-,m- and r-?) Although I do agree that it needs a good looking over.GiollaUidir 13:13, 18 October 2006 (UTC)
    Also, while most of the information does appear to be correct there are no refs given anywhere in the text!GiollaUidir 13:15, 18 October 2006 (UTC)


    Bidirectionality[edit]

    I was reading the DNA replication, and unable to find information pertaining DNA replication's bidirectionality. I think it is very important to have a section to explain the DNA's bidirectionality replication of a chromosome, as well as a contradictary example of unidirectionality. —The preceding unsigned comment was added by Wolingfeng (talkcontribs) 22:25, 6 December 2006 (UTC).

    Feedback[edit]

    I saw that people were saying how unclear the article was, so I made some changes (but am not done yet). Could someone, preferably someone who is not a molecular biologist or a biochemist :), read few of my changes, so I know if it is understandable to a more general public?

    I will make further changes/addition in upcoming days.

    also, if someone has more/better ideas, change stuff around!

    thanks, Svetlana Miljkovic 13:12, 20 December 2006 (UTC)

    bit late on the reply, but I am a bsc in biochemistry. I haven't got my textbooks in this country but I will see what I can find. If the tagging on unclear stuff could be focused into individual sections that are problematic, it would be easier to work :) it is hard to identify difficult passages, since this all makes pretty good sense to me... but I have years of training. Erk|Talk -- I like traffic lights -- 13:43, 16 February 2007 (UTC)

    DNA replication video[edit]

    http://www.wehi.edu.au/education/wehi-tv/dna/replication.html This little animation from different angles should be helpful for those interested how DNA replication works. I think we should add this link since Drew Berry made an understandable animation here...--Artman40 10:38, 30 December 2006 (UTC)

    Proposed merge[edit]

    The former content of this article appears to be at DNA replicate. I think it makes most sense to merge it back into this article here. I'm not sure why it was separated out in the first place. - tameeria 19:24, 8 March 2007 (UTC)

    I support the merge, Also DNA replicate seems to be the stronger article.
    It also seems to be 5 years newer then DNA replication Leafyplant 19:32, 8 March 2007 (UTC)
    

    Other candidates for merges include replication fork, lagging strand, and leading strand. All these are stubs right now and topics that should be part of this article. (As far as DNA replicate goes, it appears that article's content was copied from a former version of this article at the beginning of February this year, after which this article was heavily edited away from its former content so that we have two completely different articles on the same topic now.) - tameeria 19:34, 8 March 2007 (UTC)

    I'd say that DNA replicate is a product of vandalism. For some reason its removal from this page was not noticed. I agree that all stubs should probably be folded into this article and turned into redirects. If someone wishes to expand them later they still have that option. David D. (Talk) 20:40, 8 March 2007 (UTC)
    Looking at the histories more closely, I now see that the creation of DNA replicate, which was vandalism, is not associated with any major changes to this article. Interestingly, the big changes have been introduced by one wikipedian, Joe (74.97.31.113 (talk · contribs)), and they appear to be good faith edits as seen by the communication here. The two major edits include focusing more on the eucaryotic and prokaryotic sections at the expense of initiation, elongation and termination [2] and the addition of a new section on telomerase.[3] After those two edits, from late Feb, most of the constructive edits have been relatively minor.[4]. David D. (Talk) 21:06, 8 March 2007 (UTC)
    I agree that most of the changes appear to be good faith edits and might have been triggered by the existence of two identical pages on the topic. It is still the same topic though, making one page a fork of the other, and some information now is only available in one version versus the other. - tameeria 00:56, 9 March 2007 (UTC)

    As a student, I find that having separate entries is extremely useful. Maristoddard 17:07, 17 July 2007 (UTC)

    Since there's been no movement on this, I'll remove the porposed merge tag. I think the topics are probably better as separate entities to simplify this page. — Scientizzle 22:48, 8 October 2007 (UTC)

    Pro- and eukaryotic DNA replication - split or merge?[edit]

    The sections on prokaryotic DNA replication and eukaryotic DNA replication also have their own pages. Therefore, these sections could be reduced to a brief summary here. Alternatively, their pages could redirect here, so that the content is not duplicated. I'm not sure what would be the best approach, but given the amount of details, I think it might be best to keep this article general and have the specifics for pro- and eukaryotes in those other articles? - tameeria 19:43, 8 March 2007 (UTC)

    i think a very general entry level article would be great. Then the details of the processes can be expanded in the specific pro and eu articles. Certainly a discussion of the differences might be an intereszting aspect that could be developed in this article. David D. (Talk) 20:36, 8 March 2007 (UTC)
    I was the one who made the intial edits in late feb. because i thought the original article didnt go into enough details regarding the specifics of replication. My intention was to leave it as something to work on and keep the main details on DNA replication in eukaryotes, prokaryotes and now the virus, plasmid replication and D-loop replication of mitochondrial dna, all in the section because they deal with replication. while i can see the reasoning behind splitting it up, talking about all the different forms of replication on other pages, while keeping to the basics on the main page may detract from the main purpose of the article. if we structure the article better however, i am sure it will be a lot easier to read, regardless of the level of detail. furthermore, all of my edits i used the voet and voet biochemistry textbook source. Also, those two pages on pro and eu-karyotic replication is just work someone else stuck on that page that i originally added to the dna replication page:P - Joe —The preceding unsigned comment was added by 74.114.222.234 (talk) 09:18, 9 March 2007 (UTC).
    Ok, tonight I edited a lot of the page (i think). I sectioned it off, added a bunch of new information on the clamp loader, regulation of plasmid replication. I also added all the info from leading, lagging, d-loop (with my own edits), rolling circle, and replication fork pages into this one...so now we should have a more complete page. —The preceding unsigned comment was added by 74.114.222.234 (talk) 11:02, 9 March 2007 (UTC).
    Cool, thanks for your edits, Joe! It is much better structured now. Including information from biochemistry and molecular biology textbooks is good. However, since DNA replication is something kids hear about in highschool and might look up on Wikipedia, this article needs to have clearly structured basic information on the topic as well to cater to both the average highschool student and college science majors. I think it's much more balanced now. - tameeria 14:14, 9 March 2007 (UTC)

    It still needs a lot of work, and a lot of new sections need to be added to it. At the moment, I study microbiology at the university of guelph. But a lot of sections still need to be edited for more "completeness" because I either pulled them right from the wikipedia page (like d-loop, lagging/leading/replication fork) and need to be cleaned up. sorry for my bad grammer, ive been up all night doing final edits on my h2ax paper so im just a little grammered out! but I think the next major section should be archea and replication in bacterial and eukaryotic viruses. As for the way eukaryotic and prokaryotic replication is structured..i think its fine as it is now (maybe a section pointing to the mechanism of elongation and a blurb explaining that) and then the pages that you started with it could be further detailed later on...i think we also need some way to talk about checkpoints in S-phase in the eukaryotic cell cycle with regards to stalled replication forks and double strand breaks and other forms of DNA damage that can occur in DNA replication..nothing huge, but something pointing to DNA repair (And hopefully if i get a good grade on my paper, ill turn it into a wikipedia page!)..anyways, enough of my blabbing - Joe

    DNA synthesis - disambig?[edit]

    Based on previous comments, it appears the redirect of DNA synthesis to this article might be ambiguous. Besides cellular DNA replication, there is also enzymatic in vitro DNA replication (Polymerase chain reaction) and chemical DNA synthesis (oligonucleotide synthesis). Should DNA synthesis be disambiguated? Also, information on chemical DNA synthesis was requested, but I think it's beyond the scope of this article as it is not exactly replication, but de-novo synthesis via chemistry. What would be a good title for a page for that topic? Should it be at DNA synthesis, or should that be purely a disambigation page with the other maybe at Oligonucleotide synthesis? - tameeria 19:49, 8 March 2007 (UTC)

    I've created an article at oligonucleotide synthesis and added a disambiguation page for DNA synthesis. If anyone has anything to add, please feel free. - tameeria 17:35, 14 April 2007 (UTC)

    Major problems[edit]

    This page seems to be suffering from some major issues. In my opinion, it would be best to make the distinction between prokaryotic and eukaryotic DNA replication more obvious, preferably by splitting everything except the introduction in a prokaryotic and a eukaryotic section. Also, it doesn't have in-line references. Since those are preferred for good article status, I will add those in my edits. If the previous sources could be converted to in-line references it would be great. Sakkura 18:18, 13 July 2007 (UTC)

    Focus on common mechanisms?[edit]

    I feel these eubacteria / eukaryotes / archaea sections are very heavy on naming of specific enzymes rather than focusing on general mechanisms. I think it would be nice to reorganize this article with more general mechanisms of DNA replication rather than throwing case studies at the reader. I was looking at chapter 15 in DNA Replication 2nd ed (Kornberg & Baker) which lists some basic rules of replication:

    • semiconservative
    • initiation occurs at specific sequences in DNA, called origins
    • replication continues uni or bi-directionally along replication forks
    • helicase is nearly always necessary for progress of the fork
    • stands elongate in 5' to 3' direction / replication is generally semidiscontinuous / okazaki fragments
    • short fragments of RNA serve as primers

    Rather than throw three different cases at the reader, we could talk about these common features. If the differences between eukaryote and eubacteria and archaea can be boiled down into a paragraph, this would be ideal.

    It's not that the current material is wrong, but it's way, way too technical. I've got biology background and my eyes just glaze over when I read: "Activation of the complex occurs in S-phase and requires Cdk2-Cyclin E and Ddk. The activation process begins with the addition of Mcm10 to the pre-RC, which displaces Cdt1. Following this, Ddk phosphorylates Mcm3-7, which activates the helicase."

    I feel bad throwing material away, but I feel like the page needs a rewrite that focuses on common mechanisms rather than separately describing a couple of very detailed biochemical cases. I'd like to start working on it myself, please let me know if I shouldn't spend time on it. Madeleine 20:25, 1 August 2007 (UTC)

    I too would prefer if this particular article confines itself to the general mechanisms, without going into too much detail about all the specifics. Separate articles can be written about eubacteria / eukaryotes / archae can be linked from here, and things can be dealt with in more detail there. - TwoOars 20:37, 1 August 2007 (UTC)

    TOO COMPLEX[edit]

    Hey I don't know who is writing this article, but I am in 11th grade and I didn't understand much from this, remember that a lot of people check this page and has to be understandable for everyone!--189.135.137.8 20:54, 6 October 2007 (UTC)

    True. But it is a complex topic. :) But seriously, we have to strike a balance between comprehensive coverage and keeping it simple. A difficult thing to achieve. :-/ Note that it would be even more difficult to understand, if not for all the wikilinks. And a lot of the (really) gory details are pushed away to separate articles. - TwoOars (Rev) 21:25, 6 October 2007 (UTC)
    There is a Simple Wikipedia version of the page, but I doubt it'll go into enough detail for 11th grade. --Gwib (talk) 20:41, 19 February 2008 (UTC)
    I disagree. I love it. Stephen Charles Thompson (talk) 21:08, 24 April 2009 (UTC)

    I disagree also. I'm a 3rd year Med Student who just couldn't grasp this concept last year in class. HOWEVER, after reading this article, utilizing the FANTASTIC visual aides, plus visiting the word links that I didn't understand... It pulled it all together for me. The lightbulb finally turned on for me. I am so grateful, thank you. USMLE Step 1 here I come! — Preceding unsigned comment added by 12.235.208.2 (talk) 15:17, 13 November 2011 (UTC)

    Draft of new version of article[edit]

    I've finally put together a draft of a new version of this article that focuses more on common mechanisms. I've thrown away a lot of the protein naming. It would be wonderful if anyone interested could take a look at the article, make corrections, suggestions and/or mark it up with {{fact}} and {{what}} tags (I tend to write things in one fell swoop and it's hard to know which sentences should get references placed on them so it'd be nice if someone else marked which points should be referenced). Tell me what you think and maybe I can copy it over here and replace the current article. Madeleine 19:16, 3 March 2008 (UTC)

    No one said anything so I replaced the article with my version. Madeleine 01:56, 6 March 2008 (UTC)
    Thanks for your hard work re-writing the article. I had the article watched for a while now since I thought it needed great improvement but never personally got around to it. The writing is quite excellent and will hopefully be easy for a non-scientist to understand. I think with a few more referneces the article should go for GA status. Let me know if you need any help. Biomedeng (talk) 02:28, 6 March 2008 (UTC)

    DNA replication accuracy?[edit]

    In the wikipedia article it says: "DNA polymerases are generally extremely accurate, making less than one error for every million nucleotides added."

    But according to one of the sources cited:

    "As discussed at the beginning of this chapter, the fidelity of copying DNA during replication is such that only about 1 mistake is made for every 10^9 nucleotides copied."

    That makes it less than an error in 1 billion nucleotides added, not 1 million. If people agree can we change it according to the source? [5] —Preceding unsigned comment added by Medfreak (talkcontribs) 13:08, 22 August 2008 (UTC)

    We'd need a citation here. The error rate for Taq and other thermostable polymerases is 10^-5, or at best 10^-6. The "1 in a billion" number is for the entire replication machinery - that is, the entire holoenzyme, mismatch repair systems, etc., which includes a lot more than just the polymerase. Graft | talk 09:08, 4 November 2008 (UTC)

    Name of Active Site?[edit]

    I vaguely remember learning about a name for the active site where replication was occuring. Isn't there a name for this region of splitting and replicating? Isn't there a sub-organelle or micro-organelle responsible for this? Stephen Charles Thompson (talk) 21:12, 24 April 2009 (UTC)

    Do you mean "replication fork"? There's no specific organelle devoted to it - it happens wherever the DNA is lying around in the nucleus. Graft | talk 21:53, 24 April 2009 (UTC)

    Merge from Replication fork[edit]

    It was previously mentioned in this discussion, but now that the same discussion in that other article Talk:Replication fork, it's worth to bring up again. It says almost exactly the same as the section DNA replication#The replication fork and could conveniently be redirected directly to that section. Thus, there's no use reading Replication fork after reading this article, and starting with reading Replication fork without getting it in its context is also inefficient. Mikael Häggström (talk) 18:54, 21 May 2009 (UTC)

    After reading both articles, the similarity is quite apparent; the merging of these two pages makes sense in terms of completeness. However, there was an earlier discussion about the simplicity of this article. As an 11th grader I can easily understand the plight of several High School Biology students, and for their sake, I feel that these articles should remain separate. If someone needs to go deeper, (as I did) it is easy enough to follow the link and skim the repetitious material. --Adam zappul (talk) 03:54, 6 June 2010 (UTC)

    I think that the merging does make a lot of sense, being a "High School Biology student," as you put it. The replication fork is in the very first picture in the article, and is the beginning of DNA replication, so I would say it would make more sense to merge the two. --~tajt 16:41, 18 November 2010 (UTC)

    Sorry for not having an account, but I figured my voice needed to be heard. I'm currently studying for midterms in my high school and this is on the biology test and I really need this. Please keep and don't merge :) 76.250.195.66 (talk) 16:12, 18 January 2011 (UTC)

    Unclear sentences[edit]

    We have a few unclear sentences here

    1. "The energetics of this process also help explain the directionality of synthesis - if DNA were synthesized in the 3' to 5' direction, the energy for the process would come from the 5' end of the growing strand rather than from free nucleotides." So be it. Where is the problem here?
    2. "If the 5' nucleotide needs to be removed during proofreading, the triphosphate end is lost. Hence, the energy source that usually provides energy to add a new nucleotide is also lost." With what effect?

    Debresser (talk) 14:38, 4 September 2009 (UTC)

    The problem is that if the triphosphates are on the growing strand and not on the free nucleotides, proof-reading by removing a mismatched terminal nucleotide is problematic: Once a nucleotide is added, the triphosphate is lost and a single phosphate remains on the backbone between the new nucleotide and the rest of the strand. If that nucleotide is mismatched, you have to remove it and then only have one phosphate at the end of the "growing strand", not a triphosphate that is needed to attach a new nucleotide. So it's stuck and can't grow anymore.
    If the triphosphates at each step are taken from the free nucleotides, not the polymerized strand, you don't get stuck in this way.
    If you understand now and can think of what to add/change to clarify this explanation, that would be great! -- Madeleine 16:31, 4 September 2009 (UTC)
    I'm sorry, but I don't. Perhaps an expert with a talent for explaining difficult things in simple words could do this. Or we could remove it, if it is too technical for this article. Debresser (talk) 19:49, 22 September 2009 (UTC)

    Recommend link to existing Wiki topic[edit]

    In the section under Origins of Replication, there is a reference to Okazaki fragments as follows: "Once strands are separated, RNA primers are created on the template strands. More specifically, the leading strand receives one RNA primer per active origin of replication while the lagging strand receives several; these several fragments of RNA primers found on the lagging strand of DNA are called Okazaki fragments, named after their discoverer."

    It seems to me that it would be beneficial to hyperlink the term "Okazaki fragments" to the Wiki article of the same name....also possibly pluralizing the word "discoverer", since in the Okazaki fragment Wiki article two Okazakis are credited with their discovery. Just a couple of thoughts after reading the first few paragraphs of the article. 66.205.144.176 (talk) 11:12, 6 September 2010 (UTC)introspectacle

    Video clip[edit]

    I have generated a short (52 seconds / 8.5 MB) clip showing the prime phases of DNA replication. Please make comments / suggestions as to any improvement. (Not suitable for dial-up lines) --Cookatoo.ergo.ZooM (talk) 08:05, 4 November 2010 (UTC)

    File size minimised to 1.11 MB to reduce problems at load and view. --Cookatoo.ergo.ZooM (talk) 20:00, 14 November 2010 (UTC)

    Very neat! I support replacing the lead image with this video, which is in line with Wikipedia's approach to boldness and will likely generate more feedback. While it contains jargon like 'helicase' and 'polymerase', I think those terms are adequately contextualized, and could be wikilinked in a brief caption. More of this type of simple audio-video content is something that could greatly benefit science articles. Emw (talk) 04:17, 19 November 2010 (UTC)

    WP:GA Candidate[edit]

    I believe the article is good enough to be a Good Article. However not being a major contributor, it is mandatory for regular editors to be consulted prior to submission as I propose. Thoughts? --HarshAJ (Talk)(Contribs) 14:00, 13 December 2012 (UTC)

    I personally would disagree, since I believe the article is too brief, but I notice that several commentators on this talk page think that the coverage in this article is just about right. I am thus nominating the article for GA. Assuming that a fair and conscientious GA reviewer takes on this article, the close attention and scrutiny will be good for it. Stigmatella aurantiaca (talk) 00:39, 14 December 2012 (UTC)
    This is the kind of article I'd be interested in reviewing, but I think it would have problems making it out of the starting blocks with the large number of unreferenced paragraphs. I recommend withdrawing and getting the sourcing up to par. It might be possible to do this quickly, as everything should be citable to an undergrad-level textbook, but probably would be a more enjoyable task without any time pressure. Sasata (talk) 02:13, 14 December 2012 (UTC)
    Good idea! Stigmatella aurantiaca (talk) 05:32, 14 December 2012 (UTC)

    Standardise[edit]

    I noted in section 'Origin' both m-dashes and hyphens were used. It would be best to standardise on n-dashes throughout if hyphens are not appropriate. Style guide gives chapter and verse, and should be read. Sooner or later in the GA/FA process it has to be done, so best to do these things right away.

    Likewise, to add refs to unref'd paras, select one or two standard texts and stick to them. I notice you have refs to the out-of-date-edition of The Molecular Biology of the Cell. They should be adjusted to the latest edition, including the new pages numbers.

    Boring, but necessary. Macdonald-ross (talk) 12:54, 19 December 2012 (UTC)

    RNA primer addition on the lagging strand[edit]

    Currently (this exact phrasing is a result of my own recent edits, but the article was to this effect before my edits) we say: "The leading strand receives one RNA primer while the lagging strand receives several." Is the later part of this sentence accurate? Are the RNA primers added to the lagging strand as a group of several, or one at a time as the lagging strand is exposed? It is possible that with the initial formation of the pre-replication complex, several RNA primers are added. But since most Okazaki fragments are a few hundred base pairs and the pre-replication complex exposes about the same number of base pairs on the lagging strand, I would imagine only one RNA primer could be added initially. Once replication is proceeding, I would think primers would be added continuously. Thanks!Scientific29 (talk) 18:20, 20 April 2013 (UTC)

    Talk page archive[edit]

    Can I ask Miza bot to archive this talk page? The how-to page says get consensus first...Scientific29 (talk) 18:21, 20 April 2013 (UTC)

    OK with me. Most of these talk comments date from years ago. This article has an uncomfortable number of current inaccuracies that need to be addressed. It's surprising to me how many this article has, given its importance and the number of eyes that have presumably been checking and verifying it over the years. Stigmatella aurantiaca (talk) 23:13, 21 April 2013 (UTC)
    Yes this seems like an important and awful article. I guess my first question is, what do we want it to be compared to, say, Prokaryotic DNA repication and Eukaryotic DNA replication? I have a elementary understanding of DNA replication and could certainly improve this article if it were intended to be a general introduction to the topic. However, I don't really know enough to compare and contrast prokaryotic and eukaryotic replication. I'm more of a translation guy. Scientific29 (talk) 23:57, 21 April 2013 (UTC)

    Merge from Replication fork II[edit]

    Merge has been done, but the result is not completely satisfying: I find the article very long and complex and tiring to read, while some points are still not sufficiently explained. For instance I came here looking for details about "stalled replication forks", but the search returns several articles, each of them using the term but without the simplest explanation, and the one place where such an explanation could be expected, precisely "Replication Fork", does indeed mention stalled forks, but with confusing expressions like "If replication forks stall [..] daughter strands have nick obtained un-replicated sites", which are not really helpful.
    It would be useful maybe to have a shorter, more readable section "Replication Fork" in this article, with a link to a full main article "Replication Fork", where the subject could be treated really exhaustively, just like it is done in many historical articles in WP.
    This way someone could also develop the subsection "Dynamics at the replication fork", which is still somewhat lapidary and rather confusing (what are clamps necessary for? Sentences like Clamp-loading proteins are used to initially load the clamp are not really adding information. And so on), maybe because nobody dares to overload the article even more. 194.174.73.33 (talk) 17:45, 21 March 2016 (UTC) Marco Pagliero Berlin

    Assessment comment[edit]

    The comment(s) below were originally left at Talk:DNA replication/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

    The article is generally scientifically correct, but it badly needs to be translated into plainer English. – ClockworkSoul 04:48, 7 November 2006 (UTC) Changing the rating to "top" as this is high school/SAT biology topic and a central mechanism of molecular biology. - tameeria 03:40, 19 February 2007 (UTC)

    Last edited at 03:40, 19 February 2007 (UTC). Substituted at 12:40, 29 April 2016 (UTC)

    Ribopolymerase and the origins of life[edit]

    try to create ribopolymerase in the lab - a catalyst which acts as ribosome and polymerase ... — Preceding unsigned comment added by 2A02:587:4109:4C00:1819:DEC2:D0BC:9571 (talk) 00:14, 29 August 2016 (UTC)