title: An in vivo effect of the metabolites L-alanine and glycyl-L-leucine on the properties of lysyl-tRNA synthetase from Escherichia coli K-12. I. Influence on subunit composition and molecular weight distribution.
abstract: Lysyl-tRNA synthetase was purified to 70-90% of homogeneity from Escherichia coli K-12. The enzyme was purified from wild-type cells grown in minimal medium, or minimal medium containing either 20 mM L-alanine or 3 mM glycly-L-leucine. The synthetase was similarly purified from a mutant strain grown in minimal medium plus 20 mM L-alanine. Results based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, gel filtration, and trypsin inactivation studies indicate (A) that the presence of L-alanine of glycyl-L-leucine in the culture medium alters the properties of the wild-type enzyme; (B) that the alteration of the synthetase by l-alanine and glycyl-L-leucine is different; and (c) that the molecular weight of lysyl-tRNA synthetase is at least 135000--140000. The results suggest that most likely the metabolites modify the structure of lysyl-tRNA synthetase, but the possibility that the metabolites induce the synthesis of a new lysyl-tRNA synthetase cannot be completely eliminated.
mesh_terms: D000409:Alanine / Q000494:pharmacology*; D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism; D004151:Dipeptides / Q000494:pharmacology*; D004926:Escherichia coli / Q000201:enzymology*; D005998:Glycine; D007930:Leucine; D008250:Lysine-tRNA Ligase / Q000378:metabolism; D046911:Macromolecular Substances; D008970:Molecular Weight; D009154:Mutation; D011487:Protein Conformation; D013045:Species Specificity; D014357:Trypsin
chemical_list: D004151:Dipeptides; D046911:Macromolecular Substances; D014357:Trypsin; D000604:Amino Acyl-tRNA Synthetases; D008250:Lysine-tRNA Ligase; D007930:Leucine; D000409:Alanine; D005998:Glycine