A novel L-amino acid ligase from Bacillus subtilis NBRC3134 catalyzed oligopeptide synthesis.
L-Amino acid ligase catalyzes dipeptide synthesis from unprotected L-amino acids in an ATP-dependent manner. We have purified a new L-amino acid ligase, RizA, which synthesizes dipeptides whose N-terminus is Arg, from Bacillus subtilis NBRC3134, a microorganism that produces a rhizocticin peptide antibiotic. It was suggested that RizA is probably involved in rhizocticin biosynthesis. In this study, we performed sequence analysis of unknown regions around rizA, and newly identified a gene that encodes a protein that possesses an ATP-grasp motif upstream of rizA. This gene was designated rizB, and its recombinant protein was prepared. Recombinant RizB synthesized homo-oligomers of branched-chain L-amino acids and L-methionine consisting of two to five amino acids in an ATP-dependent manner. RizB also synthesized various heteropeptides. Further examination showed that RizB might elongate a peptide chain at the N-terminus. This is the first report on an L-amino acid ligase catalyzing oligopeptide synthesis.
Kino
Kuniki
K
Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, Tokyo, Japan. kkino@waseda.jp
Arai
Toshinobu
T
Tateiwa
Daisuke
D
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism*; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D055162:Biocatalysis; D006863:Hydrogen-Ion Concentration; D008025:Ligases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000096:biosynthesis*; D013696:Temperature
D000596:Amino Acids; D009842:Oligopeptides; D008025:Ligases