RESUMO
Streptococcus uberis, a causal agent of bovine mastitis, produces ubericin A, a 5.3-kDa class IIa (pediocin-like) bacteriocin, which was purified and characterized. The uba locus comprises two overlapping genes: ubaA (ubericin A precursor peptide) and ubaI (putative immunity protein). Ubericin A is the first streptococcal class IIa bacteriocin to be characterized.
Assuntos
Bacteriocinas/metabolismo , Streptococcus/metabolismo , Sequência de Aminoácidos , Animais , Bacteriocinas/química , Bacteriocinas/genética , Bovinos , DNA Bacteriano/química , DNA Bacteriano/genética , Mastite Bovina/microbiologia , Dados de Sequência Molecular , Peso Molecular , Análise de Sequência de DNA , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Streptococcus/genéticaRESUMO
Production of the novel bacteriocin streptococcin A-M57 (SA-M57) by Streptococcus pyogenes strains of M-protein type 57 is plasmid-associated. Plasmid pDN571 (3351bp) harbored by S. pyogenes 71-724, the prototype M-type 57 strain, has been completely sequenced and contains three putative open reading frames (repA, scnM57 and ORF3). In addition, the double-strand and single-strand (SSO) origins of replication were identified. Analysis of the replication-associated genetic elements places pDN571 in the ubiquitous pC194/pUB110 family of rolling-circle plasmids. The SSO of pDN571 is of the ssoA type. SA-M57 (encoded by scnM57) is synthesized as a secreted 179-amino acid polypeptide with a 27-residue secretion signal peptide and has no homology to proteins of known function.