Biosynthesis of bacitracin on a protein thiotemplate.
The dodecapeptide bacitracin A is the major constitutent of a family of antibacterial peptides produced by Bacillus licheniformis. The non-ribosomal biosynthesis of bacitracin has been studied in cell-free extracts. Bacitracin synthetase has been fractionated on Sephadex G 200 column into two fractions; both fractions were required for bacitracin biosynthesis. On the other hand, on a Sepharose affinity chromatography column, using L-leucine as ligand, three fractions were obtained; all three were required for bacitracin biosynthesis. During bacitracin synthesis, the enzyme components contain a number of thioester bound peptides. The nature of the peptides suggested that the synthesis proceeds towards the C-terminal end of the molecule. It is assumed that by sequential addition of thioester-bound amino acids, bacitracin A could be synthesized on the surface of the enzyme containing phosphopantetheine.
D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism; D049148:Aminoacylation; D001407:Bacillus / Q000201:enzymology / Q000378:metabolism*; D001414:Bacitracin / Q000096:biosynthesis*; D002474:Cell-Free System; D008025:Ligases / Q000378:metabolism; D008274:Magnesium / Q000494:pharmacology; D013698:Templates, Genetic
D000596:Amino Acids; D001414:Bacitracin; D000249:Adenosine Monophosphate; D000255:Adenosine Triphosphate; D008025:Ligases; D008274:Magnesium