title: Identification and characterization of two novel clostridial bacteriocins, circularin A and closticin 574.
abstract: 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.
authors.affiliation: Department of Molecular Genetics, Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.
authors.forename: Robèr
authors.initials: R
authors.lastname: Kemperman
authors.forename: Anneke
authors.initials: A
authors.lastname: Kuipers
authors.forename: Harma
authors.initials: H
authors.lastname: Karsens
authors.forename: Arjen
authors.initials: A
authors.lastname: Nauta
authors.forename: Oscar
authors.initials: O
authors.lastname: Kuipers
authors.forename: Jan
authors.initials: J
authors.lastname: Kok
mesh_terms: 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
chemical_list: D001426:Bacterial Proteins; D001430:Bacteriocins