RECA-MEDIATED CLEAVAGE ACTIVATES UMUD FOR MUTAGENESIS - MECHANISTIC RELATIONSHIP BETWEEN TRANSCRIPTIONAL DEREPRESSION AND POSTTRANSLATIONAL ACTIVATION
RECA-MEDIATED CLEAVAGE ACTIVATES UMUD FOR MUTAGENESIS - MECHANISTIC RELATIONSHIP BETWEEN TRANSCRIPTIONAL DEREPRESSION AND POSTTRANSLATIONAL ACTIVATION
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DOI：
10.1073/pnas.85.6.1816
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发表时间：
1988-03-01
影响因子：
11.1
通讯作者：
WALKER, GC
中科院分区：
文献类型：
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作者：
NOHMI, T;BATTISTA, JR;WALKER, GC
SOS调控的umuDC操纵子的产物是大多数紫外线和化学诱变所必需的。研究表明，UmuD蛋白与SOS基因的抑制子LexA具有同源性。在本文中，我们描述了一系列的遗传学实验，这些实验表明，RecA介导的UmuD在Cys-24和Gly-25之间的键上的裂解的目的是激活UmuD在诱变中的作用，并且UmuD的COOH-末端片段是UmuD在紫外线诱变中作用的必要条件和充分条件。其他的遗传学实验表明：(I)支持Ser-60在UmuD功能中的主要作用是在RecA介导的切割反应中起亲核作用的假设；(Ii)提出RecA在UV诱变中除了介导LexA和UmuD的切割外，还具有第三种作用的可能性。
The products of the SOS-regulated umuDC operon are required for most UV and chemical mutagenesis in Escherichia coli. It has been shown that the UmuD protein shares homology with LexA, the repressor of the SOS genes. In this paper we describe a series of genetic experiments that indicate that the purpose of RecA-mediated cleavage of UmuD at its bond between Cys-24 and Gly-25 is to activate UmuD for its role in mutagenesis and that the COOH-terminal fragment of UmuD is necessary and sufficient for the role of UmuD in UV mutagenesis. Other genetic experiments are presented that (i) support the hypothesis that the primary role of Ser-60 in UmuD function is to act as a nucleophile in the RecA-mediated cleavage reaction and (ii) raise the possibility that RecA has a third role in UV mutagenesis besides mediating the cleavage of LexA and UmuD.