title: Role of ATP and enzyme-bound nascent peptides in the control of elongation for mycobacillin synthesis.
abstract: The enzyme fraction A, a constituent of the three-fraction (A, B and C) enzyme complex mycobacillin synthetase, elongated tri- and tetra-peptides, under enzyme-bound conditions, to tetra- and penta-peptides respectively in the presence of the 'next' amino acid (in the mycobacillin sequence). The enzyme fraction B synthesized hexapeptide from free pentapeptide and the next amino acid, but synthesized heptapeptide from hexapeptide only under enzyme-bound conditions in the presence of the next amino acid. Similarly, the enzyme fraction C synthesized decapeptide from free nonapeptide in the presence of the next amino acid, but undecapeptide only from enzyme-bound decapeptide in the presence of the next amino acid during the elongation process. The Km values for the initiating reactions for each of the three enzyme fractions were 6-7-fold lower than those for the succeeding reactions catalysed by each of the enzyme fractions. The specificity of the initiation and elongation is discussed in the light of these findings.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000935:Antifungal Agents / Q000096:biosynthesis*; D001412:Bacillus subtilis / Q000201:enzymology / Q000378:metabolism; D007700:Kinetics; D046911:Macromolecular Substances; D009097:Multienzyme Complexes / Q000378:metabolism*; D009158:Mycobacillin / Q000096:biosynthesis*; D010441:Peptide Chain Elongation, Translational; D010453:Peptide Synthases / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism*
chemical_list: D000935:Antifungal Agents; D046911:Macromolecular Substances; D009097:Multienzyme Complexes; D010455:Peptides; D009158:Mycobacillin; D000255:Adenosine Triphosphate; D010453:Peptide Synthases; C042173:mycobacillin synthetase