A 2ND CHROMOSOMAL GENE NECESSARY FOR INTIMATE ATTACHMENT OF ENTEROPATHOGENIC ESCHERICHIA-COLI TO EPITHELIAL-CELLS
A 2ND CHROMOSOMAL GENE NECESSARY FOR INTIMATE ATTACHMENT OF ENTEROPATHOGENIC ESCHERICHIA-COLI TO EPITHELIAL-CELLS
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DOI：
10.1128/jb.175.15.4670-4680.1993
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发表时间：
1993-08-01
影响因子：
3.2
通讯作者：
KAPER, JB
中科院分区：
文献类型：
--
作者：
DONNENBERG, MS;YU, J;KAPER, JB
肠致病性大肠杆菌 (EPEC) 能够紧密附着在上皮细胞上并消除其微绒毛。染色体位点 eaeA（最初为 eae）对于这种效应的亲密依恋方面是必需的。我们报告了 EPEC 染色体区域的图谱，该区域位于 eaeA 基因的下游，也是亲密附着所必需的。在该区域中鉴定的开放阅读框之一中设计了同基因框内缺失突变。由于所得突变体（如 eaeA 缺失突变体）缺乏与上皮细胞紧密附着的能力，因此突变基因被命名为 eaeB。当克隆的基因重新引入质粒上时，eaeB 突变体将恢复全部活性。 eaeB 突变体仍然能够产生 intimin，即 eaeA 基因的产物。 eaeB 突变体中 intimin 的分级特性或电泳迁移率没有明显差异。通过体外转录-翻译鉴定了eaeB基因座的产物。 eaeB 基因的核苷酸序列预测出一种蛋白质，该蛋白质含有几种转氨酶共有的序列基序。这些结果表明附着和擦除效应是一种复杂的表型，依赖于 EPEC 染色体上存在的基因簇。
Enteropathogenic Escherichia coli (EPEC) is capable of attaching intimately to epithelial cells and effacing their microvilli. A chromosomal locus, eaeA (originally eae), is required for the intimate attachment aspect of this effect. We report the mapping of a region of the EPEC chromosome that is located immediately downstream of the eaeA gene and that is also necessary for intimate attachment. An isogenic in-frame deletion mutation in one of the open reading frames identified in this region was engineered. Because the resulting mutant, like an eaeA deletion mutant, is deficient in the ability to attach intimately to epithelial cells, the mutated gene is designated eaeB. Full activity is restored to the eaeB mutant when the cloned gene is reintroduced on a plasmid. The eaeB mutant remains capable of producing intimin, the product of the eaeA gene. No differences in the fractionation properties or electrophoretic mobility of intimin are apparent in the eaeB mutant. The product of the eaeB locus was identified by in vitro transcription-translation. The nucleotide sequence of the eaeB gene predicts a protein that contains a sequence motif common to several aminotransferase enzymes. These results indicate that the attaching and effacing effect is a complex phenotype dependent on a gene cluster present on the EPEC chromosome.