Biochemical and genetic characterization of enterocin A from Enterococcus faecium, a new antilisterial bacteriocin in the pediocin family of bacteriocins
Biochemical and genetic characterization of enterocin A from Enterococcus faecium, a new antilisterial bacteriocin in the pediocin family of bacteriocins
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DOI：
10.1128/aem.62.5.1676-1682.1996
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发表时间：
1996-05-01
影响因子：
4.4
通讯作者：
Nes, IF
中科院分区：
文献类型：
--
作者：
Aymerich, T;Holo, H;Nes, IF
从一株粪肠球菌中分离出一种新的细菌素。经十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、n端氨基酸测序和质谱分析，细菌素被纯化为肠球菌素A。结合氨基酸和DNA测序数据，确定肠球菌蛋白A的一级结构。它由47个氨基酸残基组成，假设4个半胱氨酸残基形成分子内二硫桥，计算出分子量为4829。质谱分析证实了其分子量。肠球菌蛋白A的氨基酸序列与从多种乳酸菌中分离出来的一组细菌素（现在称为pediocin-like bactericins）具有显著的同源性，这些细菌素包括乳杆菌属、Pediococcus、Leuconostoc和Carnobacterium。enterocin A位于细菌染色体上，对其结构基因进行测序，发现其n端有18个氨基酸残基的先导序列，在成熟过程中被去除。enterocin A引线属于双甘氨酸引线，这种引线存在于大多数其他小的非抗生素细菌素、一些抗生素和大肠杆菌素v中。在enterocin A基因的下游有第二个开放阅读框，编码一个由103个氨基酸残基组成的蛋白。该基因可能编码肠球菌素A的免疫因子，它与另一种类似肠球菌素的细菌素白细胞aul187的操纵子中的一个相似的开放阅读框具有40%的一致性。
A new bacteriocin has been isolated from an Enterococcus faecium strain. The bacteriocin, termed enterocin A, was purified to homogeneity as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, N-terminal amino acid sequencing, and mass spectrometry analysis. By combining the data obtained from amino acid and DNA sequencing, the primary structure of enterocin A was determined. It consists of 47 amino acid residues, and the molecular weight was calculated to be 4,829, assuming that the four cysteine residues form intramolecular disulfide bridges. This molecular weight was confirmed by mass spectrometry analysis. The amino acid sequence of enterocin A shared significant homology with a group of bacteriocins (now termed pediocin-like bacteriocins) isolated from a variety of lactic acid-producing bacteria, which include members of the genera Lactobacillus, Pediococcus, Leuconostoc, and Carnobacterium. Sequencing of the structural gene of enterocin A,which is located on the bacterial chromosome, revealed an N-terminal leader sequence of 18 amino acid residues, which was removed during the maturation process. The enterocin A leader belongs to the double-glycine leaders which are found among most other small nonlantibiotic bacteriocins, some lantibiotics, and colicin V. Downstream of the enterocin A gene was located a second open reading frame, encoding a putative protein of 103 amino acid residues. This gene may encode the immunity factor of enterocin A, and it shares 40% identity with a similar open reading frame in the operon of leucocin AUL 187, another pediocin-like bacteriocin.