Arginyl-tRNA synthetase from brewer's yeast. Purification, properties, and steady-state mechanism.
tRNAArg and arginyl-tRNA synthetase have been purified to homogeneity from brewer's yeast by chromatographic methods. Arginyl-tRNA synthetase is a monomeric enzyme with a molecular weight of 72000. Two active forms of the enzyme can be found, they are interconvertible. The more stable conformation is probably the natural one. Arginyl-tRNA synthetase seems to recognize arginine very specifically. No evidence for any proof-reading mechanism could be found. The steady-state mechanism is somewhat different from the types found with arginyl-tRNA synthetase from other sources. However, all these results are compatible with a concerted reaction. Simultaneously with the release of AMP or pyrophosphate an allosteric rearrangement occurs. This conversion seems to be determining for the reaction mechanism.
D000604:Amino Acyl-tRNA Synthetases / Q000302:isolation & purification*; D001126:Arginine-tRNA Ligase / Q000302:isolation & purification* / Q000378:metabolism; D055598:Chemical Phenomena; D002621:Chemistry; D007700:Kinetics; D008970:Molecular Weight; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013379:Substrate Specificity
D000604:Amino Acyl-tRNA Synthetases; D001126:Arginine-tRNA Ligase