title: Stereochemical mechanisms of tRNA methyltransferases.
abstract: Methylation of tRNA on the four canonical bases adds structural complexity to the molecule, and improves decoding specificity and efficiency. While many tRNA methylases are known, detailed insight into the catalytic mechanism is only available in a few cases. Of interest among all tRNA methylases is the structural basis for nucleotide selection, by which the specificity is limited to a single site, or broadened to multiple sites. General themes in catalysis include the basis for rate acceleration at highly diverse nucleophilic centers for methyl transfer, using S-adenosylmethionine as a cofactor. Studies of tRNA methylases have also yielded insights into molecular evolution, particularly in the case of enzymes that recognize distinct structures to perform identical reactions at the same target nucleotide.
authors: Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233 South 10th St., Philadelphia, PA 19107, USA. ya-ming.hou@jefferson.edu
authors: Ya-Ming
authors: YM
authors: Hou
authors: John J
authors: JJ
authors: Perona
mesh_terms: D001105:Archaea / Q000201:enzymology / Q000235:genetics; D001419:Bacteria / Q000201:enzymology / Q000235:genetics; D003596:Cytosine / Q000737:chemistry / Q000378:metabolism; D008745:Methylation; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional; D012343:RNA, Transfer / Q000737:chemistry* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D014529:Uridine / Q000031:analogs & derivatives / Q000096:biosynthesis / Q000737:chemistry; D012359:tRNA Methyltransferases / Q000737:chemistry* / Q000378:metabolism
chemical_list: C009182:ribothymidine; D003596:Cytosine; D012343:RNA, Transfer; D012359:tRNA Methyltransferases; D009584:Nitrogen; D014529:Uridine