title: Co-evolution of the archaeal tRNA-dependent amidotransferase GatCAB with tRNA(Asn).
abstract: The important identity elements in tRNA(Gln) and tRNA(Asn) for bacterial GatCAB and in tRNA(Gln) for archaeal GatDE are the D-loop and the first base pair of the acceptor stem. Here we show that Methanothermobacter thermautotrophicus GatCAB, the archaeal enzyme, is different as it discriminates Asp-tRNA(Asp) and Asp-tRNA(Asn) by use of U49, the D-loop and to a lesser extent the variable loop. Since archaea possess the tRNA(Gln)-specific amidotransferase GatDE, the archaeal GatCAB enzyme evolved to recognize different elements in tRNA(Asn) than those recognized by GatDE or by the bacterial GatCAB enzyme in their tRNA substrates.
authors.affiliation: Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520 8114, USA.
authors.forename: Suk
authors.initials: S
authors.lastname: Namgoong
authors.forename: Kelly
authors.initials: K
authors.lastname: Sheppard
authors.forename: R Lynn
authors.initials: RL
authors.lastname: Sherrer
authors.forename: Dieter
authors.initials: D
authors.lastname: Söll
mesh_terms: D019843:Archaeal Proteins / Q000737:chemistry*; D019143:Evolution, Molecular; D017013:Methanobacteriaceae / Q000201:enzymology*; D009690:Nucleic Acid Conformation; D019642:RNA, Archaeal / Q000737:chemistry; D012346:RNA, Transfer, Amino Acyl / Q000737:chemistry; D012348:RNA, Transfer, Asn / Q000737:chemistry*; D012351:RNA, Transfer, Gln / Q000737:chemistry; D000637:Transaminases / Q000737:chemistry*
chemical_list: D019843:Archaeal Proteins; D019642:RNA, Archaeal; D012346:RNA, Transfer, Amino Acyl; D012348:RNA, Transfer, Asn; D012351:RNA, Transfer, Gln; D000637:Transaminases