The vacB gene required for virulence in Shigella flexneri and Escherichia coli encodes the exoribonuclease RNase R
The vacB gene required for virulence in Shigella flexneri and Escherichia coli encodes the exoribonuclease RNase R
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DOI：
10.1074/jbc.273.23.14077
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发表时间：
1998-06-05
影响因子：
4.8
通讯作者：
Deutscher, MP
中科院分区：
文献类型：
--
作者：
Cheng, ZF;Zuo, YH;Deutscher, MP
vacB 是一种先前被证明是志贺氏菌和肠侵袭性大肠杆菌表达毒力所必需的基因，现已被发现编码 3'-5' 核糖核酸外切酶 RNase R。因此，克隆了。大肠杆菌vacB导致RNase R活性过度表达，克隆基因的部分缺失或中断消除了这种过度表达，vacB染色体拷贝的中断消除了内源RNase R活性；然而，RNase R 的缺失本身对细胞生长没有影响。相比之下，同时缺乏 RNase R 和多核苷酸磷酸化酶的细胞被发现无法存活。这些数据表明，RNase R 除了在毒力中发挥作用外，还参与重要的细胞功能。将 vacB 基因产物鉴定为 RNase R 应该有助于了解肠杆菌中的毒力表型是如何表达和调节的。根据这些信息，我们建议将 vacB 更名为 rnr。
vacB, a gene previously shown to be required for expression of virulence in Shigella and enteroinvasive Escherichia coli, has been found to encode the 3'-5' exoribonuclease, RNase R. Thus, cloning off. coli vacB led to overexpression of RNase R activity, and partial deletion or interruption of the cloned gene abolished this overexpression, Interruption of the chromosomal copy of vacB eliminated endogenous RNase R activity; however, the absence of RNase R by itself had no effect on cell growth. In contrast, cells lacking both RNase R and polynucleotide phosphorylase were found to be inviable. These data indicate that RNase R participates in an essential cell function in addition to its role in virulence. The identification of the vacB gene product as RNase R should aid in understanding how the virulence phenotype in enterobacteria is expressed and regulated. On the basis of this information we propose that vacB be renamed rnr.