Purification and kinetic mechanism of lysyl-tRNA synthetase from Mycobacterium smegmatis SN2.
Lysyl-tRNA synthetase [L-lys:tRNAlys ligase (AMP forming) EC:6.1.1.6] has been purified to homogeneity from Mycobacterium smegmatis SN2. The enzyme is a dimer of molecular weight 126,000 and is composed of identical subunits. A detailed analysis of the kinetic mechanism of the lysyl-tRNA synthetase has been carried out. A rapid equilibrium random ter ter mechanism is proposed based on initial velocity and product inhibition studies. There is no evidence for the formation of enzyme-bound lysyl-adenylate. The reverse reaction, studied by the deacylation of lysyl-tRNA, requires the presence of both AMP and PPi. This observation is consistent with the mechanism proposed.
D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism*; D007700:Kinetics; D008250:Lysine-tRNA Ligase / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D009161:Mycobacterium / Q000201:enzymology*; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism
D012346:RNA, Transfer, Amino Acyl; D000604:Amino Acyl-tRNA Synthetases; D008250:Lysine-tRNA Ligase