Disruption of Escherichia coli HepA, an RNA polymerase-associated protein, causes UV sensitivity
Disruption of Escherichia coli HepA, an RNA polymerase-associated protein, causes UV sensitivity
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DOI：
10.1074/jbc.273.24.15157
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发表时间：
1998-06-12
影响因子：
4.8
通讯作者：
Severinov, K
中科院分区：
文献类型：
--
作者：
Muzzin, O;Campbell, EA;Severinov, K
在大肠杆菌RNA聚合酶(RNAP)纯化程序的开发过程中，我们注意到110 kDa多肽的一致共纯化。在这里，我们报告了110 kDa的蛋白是HEPA基因的产物，该基因是可能的解旋酶SNF2家族的成员。我们克隆了HEPA基因，并高效表达和纯化了HEPA蛋白。我们在体外表明，RNAP制剂只有在HEPA存在的情况下才具有ATPase活性，并且HEPA以1：1的化学计量比和75 nM的解离常数(K-d)竞争性地与核心RNAP与启动子特异性的sigma(70)亚基结合。一株HEPA基因突变的大肠杆菌菌株对紫外线很敏感。
During the development of purification procedures for Escherichia coli RNA polymerase (RNAP), we noticed the consistent co-purification of a 110-kDa polypeptide. Here, we report the identification of the 110-kDa protein as the product of the hepA gene, a member of the SNF2 family of putative helicases. We have cloned the hepA gene and overexpressed and purified the HepA protein. We show in vitro that RNAP preparations have an ATPase activity only in the presence of HepA and that HepA binds core RNAP competitively with the promoter specificity sigma(70) subunit with a 1:1 stoichiometry and a dissociation constant (K-d) Of 75 nM. An E. coli strain with a disruption in the hepA gene shows sensitivity to ultraviolet light.