title: ATP-analogues as substrates for the leucyl-tRNA synthetase from Escherichia coli MRE 600.
abstract: No analogous nucleoside triphosphate was found which acts as well as ATP in binding to and supporting catalysis of leucyl-tRNA synthetase from Escherichia coli MRE 600. However, there are numerous nucleotides which are able to replace ATP, but with lower efficiency. The 6-amino group of the adenine ring and the 2'-hydroxyl group of the ribose ring are essential for binding and catalytic activity. Alterations in the triphosphate moiety of the molecule can cause drastic changes in Km and/or Vmax, whereas alterations of the imidazole ring and substitutions at the 8-position of the adenine ring cause only minor losses of catalytic activity.
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives*; D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism*; D001667:Binding, Competitive; D004926:Escherichia coli / Q000201:enzymology*; D007700:Kinetics; D007935:Leucine-tRNA Ligase / Q000378:metabolism*; D011485:Protein Binding; D013329:Structure-Activity Relationship
chemical_list: D000255:Adenosine Triphosphate; D000604:Amino Acyl-tRNA Synthetases; D007935:Leucine-tRNA Ligase