title: The gene cluster of aureocyclicin 4185: the first cyclic bacteriocin of Staphylococcus aureus.
abstract: Staphylococcus aureus 4185 was previously shown to produce at least two bacteriocins. One of them is encoded by pRJ101. To detect the bacteriocin-encoding gene cluster, an ~9160 kb region of pRJ101 was sequenced. In silico analyses identified 10 genes (aclX, aclB, aclI, aclT, aclC, aclD, aclA, aclF, aclG and aclH) that might be involved in the production of a novel cyclic bacteriocin named aureocyclicin 4185. The organization of these genes was quite similar to that of the gene cluster responsible for carnocyclin A production and immunity. Four putative proteins encoded by these genes (AclT, AclC, AclD and AclA) also exhibited similarity to proteins encoded by cyclic bacteriocin gene clusters. Mutants derived from insertion of Tn917-lac into aclC, aclF, aclH and aclX were affected in bacteriocin production and growth. AclX is a 205 aa putative protein not encoded by the gene clusters of other cyclic bacteriocins. AclX exhibits 50 % similarity to a permease and has five putative membrane-spanning domains. Transcription analyses suggested that aclX is part of the aureocyclicin 4185 gene cluster, encoding a protein required for bacteriocin production. The aclA gene is the structural gene of aureocyclicin 4185, which shows 65 % similarity to garvicin ML. AclA is proposed to be cleaved off, generating a mature peptide with a predicted Mr of 5607 Da (60 aa). By homology modelling, AclA presents four α-helices, like carnocyclin A. AclA could not be found at detectable levels in the culture supernatant of a strain carrying only pRJ101. To our knowledge, this is the first report of a cyclic bacteriocin gene cluster in the genus Staphylococcus.
authors.affiliation: Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, UFRJ, Rio de Janeiro, Brazil.
authors.forename: Amina
authors.initials: A
authors.lastname: Potter
authors.affiliation: Instituto Federal de Educação Tecnológica do Estado do Rio de Janeiro, IFRJ, Rio de Janeiro, Brazil.|Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, UFRJ, Rio de Janeiro, Brazil.
authors.forename: Hilana
authors.initials: H
authors.lastname: Ceotto
authors.affiliation: Instituto Nacional da Propriedade Industrial, INPI, Rio de Janeiro, Brazil.|Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, UFRJ, Rio de Janeiro, Brazil.
authors.forename: Marcus Lívio Varella
authors.initials: MLV
authors.lastname: Coelho
authors.affiliation: Universidade Federal Fluminense, UFF, Niterói, Brazil.
authors.forename: Allan J
authors.initials: AJ
authors.lastname: Guimarães
authors.affiliation: Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, UFRJ, Rio de Janeiro, Brazil.
authors.forename: Maria do Carmo de Freire
authors.initials: MDCF
authors.lastname: Bastos
mesh_terms: D001430:Bacteriocins / Q000096:biosynthesis* / Q000235:genetics*; D053898:Biosynthetic Pathways / Q000235:genetics*; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D020869:Gene Expression Profiling; D023061:Gene Order; D008969:Molecular Sequence Data; D005810:Multigene Family; D016254:Mutagenesis, Insertional; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013211:Staphylococcus aureus / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*
chemical_list: D001430:Bacteriocins; D004251:DNA Transposable Elements; D004269:DNA, Bacterial