Mechanism of protein remodeling by ClpA chaperone.
Mechanism of protein remodeling by ClpA chaperone.
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ClpA 伴侣蛋白重塑的机制。
DOI：
--
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发表时间：
1997
影响因子：
11.1
通讯作者：
S. Wickner
中科院分区：
文献类型：
--
作者：
M. Pak;S. Wickner
ClpA是一种新发现的依赖atp的分子伴侣，它将噬菌体P1的RepA二聚体重塑为单体，从而激活RepA潜在的特异性DNA结合活性。我们通过将反应分解成几个步骤并确定核苷酸在每个步骤中的作用来研究ClpA伴侣活性的机制。在ATP或不可水解的ATP类似物存在的情况下，初始步骤是ClpA的自组装及其与非活性RepA二聚体的结合。ClpA-RepA络合物在0℃下迅速形成，但相对不稳定。下一步是将不稳定的ClpA-RepA复合物在时间和温度依赖的反应中转化为稳定的复合物。过渡到稳定的ClpA-RepA复合物需要ATP结合，而不是ATP水解，因为不可水解的ATP类似物满足核苷酸需求。稳定的配合物每1 mol ClpA六聚体含有约1 mol RepA二聚体，并致力于激活RepA。在反应的最后一步，活性RepA通过ATP与不可水解的ATP类似物交换和ATP水解而释放。重要的是，我们发现RepA与ClpA结合的一个周期，随后是atp依赖性释放，足以将非活性RepA转化为活性形式。
ClpA, a newly discovered ATP-dependent molecular chaperone, remodels bacteriophage P1 RepA dimers into monomers, thereby activating the latent specific DNA binding activity of RepA. We investigated the mechanism of the chaperone activity of ClpA by dissociating the reaction into several steps and determining the role of nucleotide in each step. In the presence of ATP or a nonhydrolyzable ATP analog, the initial step is the self-assembly of ClpA and its association with inactive RepA dimers. ClpA-RepA complexes form rapidly and at 0 degrees C but are relatively unstable. The next step is the conversion of unstable ClpA-RepA complexes into stable complexes in a time- and temperature-dependent reaction. The transition to stable ClpA-RepA complexes requires binding of ATP, but not ATP hydrolysis, because nonhydrolyzable ATP analogs satisfy the nucleotide requirement. The stable complexes contain approximately 1 mol of RepA dimer per mol of ClpA hexamer and are committed to activating RepA. In the last step of the reaction, active RepA is released upon exchange of ATP with the nonhydrolyzable ATP analog and ATP hydrolysis. Importantly, we discovered that one cycle of RepA binding to ClpA followed by ATP-dependent release is sufficient to convert inactive RepA to its active form.
大肠杆菌的 ClpX 蛋白激活链转移复合物中的噬菌体 Mu 转座酶，启动 Mu DNA 合成。
DOI：
--
发表时间：
1996
期刊：
The EMBO journal
影响因子：
--
作者：
Kruklitis,R;Welty,DJ;Nakai,H
通讯作者：
Nakai,H
DOI：
10.1073/pnas.91.22.10345
发表时间：
1994-10-25
影响因子：
11.1
作者：
SZABO, A;LANGER, T;HARTL, FU
通讯作者：
HARTL, FU