title: Pyrrolysine encoded by UAG in Archaea: charging of a UAG-decoding specialized tRNA.
abstract: Pyrrolysine is a lysine derivative encoded by the UAG codon in methylamine methyltransferase genes of Methanosarcina barkeri. Near a methyltransferase gene cluster is the pylT gene, which encodes an unusual transfer RNA (tRNA) with a CUA anticodon. The adjacent pylS gene encodes a class II aminoacyl-tRNA synthetase that charges the pylT-derived tRNA with lysine but is not closely related to known lysyl-tRNA synthetases. Homologs of pylS and pylT are found in a Gram-positive bacterium. Charging a tRNA(CUA) with lysine is a likely first step in translating UAG amber codons as pyrrolysine in certain methanogens. Our results indicate that pyrrolysine is the 22nd genetically encoded natural amino acid.
authors.affiliation: Department of Microbiology, Ohio State University, Columbus, OH 43210, USA.
authors.forename: Gayathri
authors.initials: G
authors.lastname: Srinivasan
authors.forename: Carey M
authors.initials: CM
authors.lastname: James
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Krzycki
mesh_terms: D000595:Amino Acid Sequence; D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000926:Anticodon; D019843:Archaeal Proteins; D001483:Base Sequence; D020134:Catalytic Domain; D003062:Codon; D018388:Codon, Terminator; D007700:Kinetics; D008239:Lysine / Q000031:analogs & derivatives / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017021:Methanosarcina barkeri / Q000737:chemistry / Q000201:enzymology / Q000235:genetics*; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D014176:Protein Biosynthesis; D019642:RNA, Archaeal / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012343:RNA, Transfer / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D000926:Anticodon; D019843:Archaeal Proteins; D003062:Codon; D018388:Codon, Terminator; D019642:RNA, Archaeal; D011994:Recombinant Proteins; D012343:RNA, Transfer; D008780:Methyltransferases; C103170:dimethylamine-coenzyme M methyltransferase; C113200:monomethylamine methyltransferase; D000604:Amino Acyl-tRNA Synthetases; C456839:pyrrolysine; D008239:Lysine