Kemperman Robèr, Jonker Marnix, Nauta Arjen, Kuipers Oscar P, Kok Jan
Department of Molecular Genetics, Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.
Appl Environ Microbiol. 2003 Oct;69(10):5839-48. doi: 10.1128/AEM.69.10.5839-5848.2003.
A region of 12 kb flanking the structural gene of the cyclic antibacterial peptide circularin A of Clostridium beijerinckii ATCC 25752 was sequenced, and the putative proteins involved in the production and secretion of circularin A were identified. The genes are tightly organized in overlapping open reading frames. Heterologous expression of circularin A in Enterococcus faecalis was achieved, and five genes were identified as minimally required for bacteriocin production and secretion. Two of the putative proteins, CirB and CirC, are predicted to contain membrane-spanning domains, while CirD contains a highly conserved ATP-binding domain. Together with CirB and CirC, this ATP-binding protein is involved in the production of circularin A. The fifth gene, cirE, confers immunity towards circularin A when expressed in either Lactococcus lactis or E. faecalis and is needed in order to allow the bacteria to produce bacteriocin. Additional resistance against circularin A is conferred by the activity of the putative transporter consisting of CirB and CirD.
对拜氏梭菌ATCC 25752的环状抗菌肽circularin A结构基因两侧12 kb的区域进行了测序，并鉴定了参与circularin A产生和分泌的推定蛋白。这些基因在重叠的开放阅读框中紧密排列。实现了circularin A在粪肠球菌中的异源表达，并鉴定出五个对细菌素产生和分泌来说是最低限度必需的基因。两个推定蛋白CirB和CirC预计含有跨膜结构域，而CirD含有高度保守的ATP结合结构域。这个ATP结合蛋白与CirB和CirC一起参与circularin A的产生。第五个基因cirE在乳酸乳球菌或粪肠球菌中表达时赋予对circularin A的免疫性，并且是细菌产生细菌素所必需的。由CirB和CirD组成的推定转运蛋白的活性赋予了对circularin A的额外抗性。
