Identification and characterization of two novel clostridial bacteriocins, circularin A and closticin 574.
Two novel antibacterial peptides of clostridial species were purified, N-terminally sequenced, and characterized. Moreover, their structural genes were identified. Closticin 574 is an 82-amino-acid bacteriocin produced by Clostridium tyrobutyricum ADRIAT 932. The supernatant of the producing strain showed a high level of activity against the indicator strain C. tyrobutyricum. The protein is synthesized as a preproprotein that is possibly secreted via the general secretion pathway, after which it is hydrolyzed at an Asp-Pro site. Circularin A is produced by Clostridium beijerinckii ATCC 25752 as a prepeptide of 72 amino acids. Cleavage of the prepeptide between the third leucine and fourth valine residues followed by a head-to-tail ligation between the N and C termini creates a circular antimicrobial peptide of 69 amino acids. The unusually small circularin A leader peptide of three amino acids is cleaved off in this process. The supernatant of C. beijerinckii ATCC 25752 showed a broad antibacterial activity range.
Kemperman
Robèr
R
Department of Molecular Genetics, Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.
Kuipers
Anneke
A
Karsens
Harma
H
Nauta
Arjen
A
Kuipers
Oscar
O
Kok
Jan
J
D000595:Amino Acid Sequence; D001419:Bacteria / Q000187:drug effects; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D001430:Bacteriocins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D001483:Base Sequence; D003013:Clostridium / Q000254:growth & development / Q000378:metabolism*; D005798:Genes, Bacterial; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data
D001426:Bacterial Proteins; D001430:Bacteriocins