霍乱弧菌O1型编码溶血磷脂酶L2的染色体区域的遗传分析。

Genetic analysis of the chromosomal region encoding lysophospholipase L2 of Vibrio cholerae O1.

作者信息

Whayeb S A, Yamamoto K, Tojo H, Honda T

机构信息

Department of Bacterial Infections, Research Institute for Microbial Diseases, Osaka University, Japan.

出版信息

Biochim Biophys Acta. 1996 Mar 29;1300(1):1-4. doi: 10.1016/0005-2760(95)00234-0.

DOI:10.1016/0005-2760(95)00234-0

PMID:8608155

Abstract

From the Tn5-inserted mutant library of Vibrio cholerae O1, we found a mutant, NF404, which lost the production of both hemolysin and cholera toxin (CT) even though the Tn5-insertion site was out side from the structural genes for hemolysin and CT. Cloning and sequencing analysis of the homologous region from the wild-type strain, revealed that the sequence spanning the coding region of an ORF1 nominated as lypA, encoding a 39.5 kDa protein. Deduced amino acid sequence of the lypA gene had 37.6% identity to the lysophospholipase L2 (EC 3.1.1.5) of Escherichia coli. In the downstream of lypA, a second open reading frame (ORF2) encoding an unknown protein with molecular weight of 19.9 kDa was found. Assaying the lysophospholipase L2 activity in the cell extract of E.coli harboring lypA in an expression vector showed clear increase in the enzymatic activity.

摘要

从霍乱弧菌O1的Tn5插入突变体文库中，我们发现了一个突变体NF404，尽管Tn5插入位点位于溶血素和霍乱毒素（CT）的结构基因之外，但该突变体却丧失了溶血素和霍乱毒素的产生能力。对野生型菌株同源区域的克隆和测序分析表明，跨越一个命名为lypA的开放阅读框（ORF1）编码区的序列，该ORF1编码一种39.5 kDa的蛋白质。lypA基因推导的氨基酸序列与大肠杆菌的溶血磷脂酶L2（EC 3.1.1.5）具有37.6%的同一性。在lypA的下游，发现了第二个开放阅读框（ORF2），其编码一种分子量为19.9 kDa的未知蛋白质。对在表达载体中携带lypA的大肠杆菌细胞提取物中的溶血磷脂酶L2活性进行测定，结果显示酶活性明显增加。