Bowl-shaped oligomeric structures on membranes as DegP's new functional forms in protein quality control
Bowl-shaped oligomeric structures on membranes as DegP's new functional forms in protein quality control
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膜上的碗状寡聚结构作为 DegP 在蛋白质质量控制中的新功能形式
DOI：
10.1073/pnas.0811780106
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发表时间：
2009-03-24
影响因子：
11.1
通讯作者：
Sui, Sen-Fang
中科院分区：
文献类型：
--
作者：
Shen, Qing-Tao;Bai, Xiao-Chen;Sui, Sen-Fang
在大肠杆菌的周质中，DegP(也称为HtrA)具有伴侣样活性和蛋白水解性，可以防止有毒的错误折叠和未折叠多肽的积累。在溶液中，DegP与变性蛋白结合后形成大的笼状结构。在这里，我们证明了DegP在脂膜上形成了一系列独立于底物蛋白的碗状结构，每个结构具有4-、5-或6倍的对称性，并且都以DegP三聚体为结构单元。这些膜结合的DegP组件具有在碗中招募和处理底物的能力，并且它们显示出比DegP在溶液中更高的蛋白水解性和更低的伴侣样活性。我们的发现表明，DegP可能调节其在蛋白质质量控制中的双重作用，这取决于它在狭窄的细菌被膜中的组装状态。
In the periplasm of Escherichia coli, DegP (also known as HtrA), which has both chaperone-like and proteolytic activities, prevents the accumulation of toxic misfolded and unfolded polypeptides. In solution, upon binding to denatured proteins, DegP forms large cage-like structures. Here, we show that DegP forms a range of bowl-shaped structures, independent of substrate proteins, each with a 4-, 5-, or 6-fold symmetry and all with a DegP trimer as the structural unit, on lipid membranes. These membrane-bound DegP assemblies have the capacity to recruit and process substrates in the bowl chamber, and they exhibit higher proteolytic and lower chaperone-like activities than DegP in solution. Our findings imply that DegP might regulate its dual roles during protein quality control, depending on its assembly state in the narrow bacterial envelope.