User:Knarfy/mt-tRNA Enoplea

Armless mt-tRNAs in Enoplea (Nematoda)

Mitochondrial transfer RNAs (mt-tRNA) are RNA molecules that are required for the protein biosynthesis in mitochondria. Animal mitogenomes usually encode 22 mitochondrial tRNA genes. In contrast to their nuclear counterparts, mitochondrial tRNA evolve rapidly at sequence level and exhibit a variety of deviations from the common clover-leaf structure ^[1]^[2]. Such "bizarre" mitochondrial tRNAs with incomplete clover-leaf structures have long been known in particular in the Nematoda^[3]. For example, in Caenorhabditis elegans, 20 of the 22 mt-tRNA are T-armless, and the two serine tRNAs lack the D-arm.

Computational studies^[4] of Enoplea mitogenomes discovered aberrant mitochondrial tRNA genes that have a length of only about 40 nucleotides. They lack both the D- and T-stem. Instead, these short mt-tRNA sequences formed D- and T-stem replacement loops and share only the acceptor stem and the anticodon stem with common tRNA sequences.

These armless, minimal mt-tRNAs code for Alanine, Arginine, Asparagine, Cysteine, Histidine, Isoleucine, Phenylalanine, Threonine, Tyrosine, and Valine. While not all Enoplea have the same set of degenerated genes, the members of the genus Romanomermis share 9 of the 10 genes in the aberrant genes.

An example of an aberrant tRNA^Tyr in Romanomermis nielseni (right) in comparison to Homo sapiens (left) and C. elegans (center)

References

^ Arcari, Paolo; Brownlee, George G. (1980). "The nucleotide sequence of a small (3S) seryl-tRNA (anticodon GCU) from beef heart mitochondria". Nucleic Acids Research. 8 (22): 5207???5212. doi:10.1093/nar/8.22.5207. ISSN 0305-1048.
^ de Bruijn, M.H.L.; Schreier, P.H.; Eperon, I.C.; Barrell, B.G.; Chen, E.Y.; Armstrong, P.W.; Wong, J.F.H.; Roe, B.A. (1980). "A mammalian mitochondrial serine transfer RNA lacking the "dihydrouridine" loop and stem". Nucleic Acids Research. 8 (22): 5213???5222. doi:10.1093/nar/8.22.5213. ISSN 0305-1048.
^ Wolstenholme, D.R.; Macfarlane, J.L.; Okimoto, R.; Clary, D.O.; Wahleithner, J.A. (1987). "Bizarre tRNAs inferred from DNA sequences of mitochondrial genomes of nematode worms". Proceedings of the National Academy of Sciences of the United States of America. 84 (5): 1324–1328.
^ Jühling, F.; P¨tz, J.; Florentz, C.; Stadler, P.F. (2012). "Armless Mitochondrial tRNAs in Enoplea (Nematoda)". in preparation. {{cite journal}}: line feed character in |title= at position 23 (help)CS1 maint: multiple names: authors list (link)

[ArcariBrownlee1980-1] Arcari, Paolo; Brownlee, George G. (1980). "The nucleotide sequence of a small (3S) seryl-tRNA (anticodon GCU) from beef heart mitochondria". Nucleic Acids Research. 8 (22): 5207???5212. doi:10.1093/nar/8.22.5207. ISSN 0305-1048.

[de_BruijnSchreier1980-2] Bruijn, M.H.L.; Schreier, P.H.; Eperon, I.C.; Barrell, B.G.; Chen, E.Y.; Armstrong, P.W.; Wong, J.F.H.; Roe, B.A. (1980). "A mammalian mitochondrial serine transfer RNA lacking the "dihydrouridine" loop and stem". Nucleic Acids Research. 8 (22): 5213???5222. doi:10.1093/nar/8.22.5213. ISSN 0305-1048.

[Wolstenholme1987-3] Wolstenholme, D.R.; Macfarlane, J.L.; Okimoto, R.; Clary, D.O.; Wahleithner, J.A. (1987). "Bizarre tRNAs inferred from DNA sequences of mitochondrial genomes of nematode worms". Proceedings of the National Academy of Sciences of the United States of America. 84 (5): 1324–1328.

[Juehling12-4] Jühling, F.; P¨tz, J.; Florentz, C.; Stadler, P.F. (2012). "Armless Mitochondrial tRNAs in Enoplea (Nematoda)". in preparation. {{cite journal}}: line feed character in |title= at position 23 (help)CS1 maint: multiple names: authors list (link)

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