Co-evolution of the archaeal tRNA-dependent amidotransferase GatCAB with tRNA(Asn).
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.
Namgoong
Suk
S
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520 8114, USA.
Sheppard
Kelly
K
Sherrer
R Lynn
RL
Söll
Dieter
D
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*
D019843:Archaeal Proteins; D019642:RNA, Archaeal; D012346:RNA, Transfer, Amino Acyl; D012348:RNA, Transfer, Asn; D012351:RNA, Transfer, Gln; D000637:Transaminases