Nucleotidyltransferase

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Nucleotidyltransferases are transferase enzymes of phosphorus-containing groups, e.g., substituents of nucleotidylic acids or simply nucleoside monophosphates. The general reaction of transferring a nucleoside monophosphate moiety from A to B, can be written as:

A-P-N + B \rightleftharpoons A + B-P-N

For example, in the case of polymerases, A is pyrophosphate and B is the nascent polynucleotide. They are classified under EC number 2.7.7 and they can be categorised into:

  1. Uridylyltransferases, which transfer uridylyl- groups
  2. Adenylyltransferases, which transfer adenylyl- groups
  3. Guanylyltransferases, which transfer guanylyl- groups
  4. Cytitidylyltransferases, which transfer cytidylyl- groups
  5. Thymidylyltransferases, which transfer thymidylyl- groups

Role in DNA repair mechanisms[edit]

Nucleotidyl transferase is a component of the repair pathway for single nucleotide base excision repair. This repair mechanism begins when a single nucleotide is recognized by DNA glycosylase as incorrectly matched or has been mutated in some way (UV light, chemical mutagen, etc.), and is removed. Later, a nucleotidyl tranferase is used to fill in the gap with the correct base, using the template strand as the reference. [1]

References[edit]

  1. ^ Yuan Liu, Rajendra Prasad, William A. Beard, Padmini S. Kedar, Esther W. Hou, David D. Shock, and Samuel H. Wilson (May 4, 2007). "Coordination of Steps in Single-nucleotide Base Excision Repair Mediated by Apurinic/Apyrimidinic Endonuclease 1 and DNA Polymerase β". Journal of Biological Chemistry 282 (18): 13532–13541. doi:10.1074/jbc.M611295200. PMC 2366199. PMID 17355977. "The enzymes and accessory factors involved in the BER subpathways in mammalian cells have received considerable attention. As summarized above, five distinct enzymatic reaction are involved during SN-BER. These are 1) removal of a modified base by a lesion-specific monofunctional DNA N-glycosylase, 2) 5'-incision of the abasic site by a hydrolytic strand incision enzyme, 3) DNA synthesis by a nucleotidyltransferase, 4) removal of the 5'-dRP group by a'-elimination reaction, and 5) nick sealing by DNA ligase (36, 37)" 

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