ClpX and MuB interact with overlapping regions of Mu transposase: Implications for control of the transposition pathway
ClpX and MuB interact with overlapping regions of Mu transposase: Implications for control of the transposition pathway
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DOI：
10.1101/gad.11.12.1561
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发表时间：
1997-06-15
影响因子：
10.5
通讯作者：
Baker, TA
中科院分区：
文献类型：
--
作者：
Levchenko, I;Yamauchi, M;Baker, TA
噬菌体Mu的转座由一种非常稳定的转座酶-DNA复合物催化。一旦重组完成，大肠杆菌ClpX蛋白（Clp/Hsp 100分子伴侣家族的成员）启动复合物的分解，以开始噬菌体DNA复制。为了了解重组和复制之间的转换是如何控制的，我们研究了转座酶-DNA复合物如何被ClpX识别。我们发现，从转座酶的羧基末端结构域的10个氨基酸的肽是需要其识别ClpX。这种短的带正电荷的肽也足以将异源蛋白转化为ClpX底物。与转座激活因子MuB蛋白相互作用的转座酶区域也被进一步定义，并发现与ClpX识别的区域重叠。因此，MuB抑制重组中间体的几种转座酶-DNA复合物的分解。MuB阻断转座酶的这种能力表明了在复制转座期间将ClpX介导的重塑限制到适当阶段的机制。我们建议，重叠的序列参与亚基相互作用和那些针对蛋白质的重塑或破坏可能是一个有用的设计蛋白质的功能，在重塑或降解的途径必须进行调节。
Transposition of phage Mu is catalyzed by an extremely stable transposase-DNA complex. Once recombination is complete, the Escherichia coli ClpX protein, a member of the Clp/Hsp100 chaperone family, initiates disassembly of the complex for phage DNA replication to commence. To understand how the transition between recombination and replication is controlled, we investigated how transposase-DNA complexes are recognized by ClpX. We find that a 10-amino-acid peptide from the carboxy-terminal domain of transposase is required for its recognition by ClpX. This short, positively charged peptide is also sufficient to convert a heterologous protein into a ClpX substrate. The region of transposase that interacts with the transposition activator, MuB protein, is also defined further and found to overlap with that recognized by ClpX. As a consequence, MuB inhibits disassembly of several transposase-DNA complexes that are intermediates in recombination. This ability of MuB to block access to transposase suggests a mechanism for restricting ClpX-mediated remodeling to the proper stage during replicative transposition. We propose that overlap of sequences involved in subunit interactions and those that target a protein for remodeling or destruction may be a useful design for proteins that function in pathways where remodeling or degradation must be regulated.