Mutations in the C-terminal fragment of DnaK affecting peptide binding
Mutations in the C-terminal fragment of DnaK affecting peptide binding
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DOI：
10.1073/pnas.93.20.10632
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发表时间：
1996-10-01
影响因子：
11.1
通讯作者：
Gottesman, ME
中科院分区：
文献类型：
--
作者：
Burkholder, WF;Zhao, X;Gottesman, ME
大肠杆菌DnaK通过其ATP调节的多肽底物的结合和释放作为分子伴侣。过量表达含有多肽底物结合结构域的DnaK的C-末端片段（CTF）（Gly-384至Lys-638）在野生型E.通过选择非细胞毒性CTF突变体随后进行体外筛选来鉴定影响DnaK底物结合的突变。在CTF的三维结构中这些突变的聚类提示了环L（1，2）和L（4，5）形成对于与基底相互作用至关重要的刚性核心结构。
Escherichia coli DnaK acts as a molecular chaperone through its ATP-regulated binding and release of polypeptide substrates. Overexpressing a C-terminal fragment (CTF) of DnaK (Gly-384 to Lys-638) containing the polypeptide substrate binding domain is lethal in wild-type E. coli, This dominant-negative phenotype may result from the nonproductive binding of CTF to cellular polypeptide targets of DnaK, Mutations affecting DnaK substrate binding were identified by selecting noncytotoxic CTF mutants followed by in vitro screening, The clustering of such mutations in the three-dimensional structure of CTF suggests the model that loops L(1,2) and L(4,5) form a rigid core structure critical for interactions with substrate.