A bacterial ortholog of class II lysyl-tRNA synthetase activates lysine.
Aminoacyl-tRNA synthetases produce aminoacyl-tRNAs, essential substrates for accurate protein synthesis. Beyond their central role in translation some of these enzymes or their orthologs are recruited for alternative functions, not always related to their primary cellular role. We investigate here the enzymatic properties of GenX (also called PoxA and YjeA), an ortholog of bacterial class II lysyl-tRNA synthetase. GenX is present in most Gram-negative bacteria and is homologous to the catalytic core of lysyl-tRNA synthetase, but it lacks the amino terminal anticodon binding domain of the latter enzyme. We show that, in agreement with its well-conserved lysine binding site, GenX can activate in vitro l-lysine and lysine analogs, but does not acylate tRNA(Lys) or other cellular RNAs.
Ambrogelly
Alexandre
A
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114, USA. alex.ambrogelly@gmail.com
O'Donoghue
Patrick
P
Söll
Dieter
D
Moses
Sarath
S
D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000926:Anticodon; D001665:Binding Sites / Q000235:genetics; D020134:Catalytic Domain / Q000235:genetics; D008239:Lysine / Q000235:genetics / Q000378:metabolism; D008250:Lysine-tRNA Ligase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012346:RNA, Transfer, Amino Acyl / Q000235:genetics / Q000378:metabolism
D000926:Anticodon; D012346:RNA, Transfer, Amino Acyl; D000604:Amino Acyl-tRNA Synthetases; D008250:Lysine-tRNA Ligase; D008239:Lysine