Structure and expression of a gene encoding the precursor of subtilin, a small protein antibiotic.
A gene has been cloned from Bacillus subtilis ATCC 6633 that encodes a 56-residue peptide precursor for the 32-residue peptide antibiotic, subtilin. The precursor contains serines, threonines, and cysteines at positions that permit them to undergo a series of dehydration and cross-linking steps to give the mature antibiotic peptide which contains the unusual amino acids lanthionine, beta-methyllanthionine, D-alanine, dehydroalanine, and dehydrobutyrine. The precursor peptide contains a leader region that has an unusual hydropathic character for an exported protein. The subtilin gene is expressed from a monocistronic transcriptional unit as identified by S1 mapping of the gene transcript. The (-35) region of the promoter is not typical of Bacillus subtilis vegetatively-expressed genes. The subtilin transcript was present in very low amounts during exponential growth, but in large amounts during stationary phase; at which time mature subtilin peptide and antibiotic activity were also observed. The subtilin transcript contains a cleavage-sensitive region that overlaps the ribosome binding site. The primary transcript has an unusually long half-life of about 45 min. These observations confirm that subtilin is derived from a small protein that is synthesized on ribosomes.
Banerjee
S
S
Department of Chemistry and Biochemistry, University of Maryland, College Park 20742.
Hansen
J N
JN
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D001412:Bacillus subtilis / Q000235:genetics* / Q000254:growth & development; D001426:Bacterial Proteins; D001430:Bacteriocins; D001483:Base Sequence; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes; D005796:Genes; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization; D010455:Peptides / Q000235:genetics*; D011498:Protein Precursors / Q000235:genetics*
D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D001426:Bacterial Proteins; D001430:Bacteriocins; D010455:Peptides; D011498:Protein Precursors; D004262:DNA Restriction Enzymes; C002836:subtilin