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Bowl-shaped oligomeric structures on membranes as DegP's new functional forms in protein quality control.

ABSTRACT: 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.

SUBMITTER: Shen QT

PROVIDER: S-EPMC2660739 | biostudies-literature | 2009 Mar

REPOSITORIES: biostudies-literature

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Bowl-shaped oligomeric structures on membranes as DegP's new functional forms in protein quality control.

Shen Qing-Tao QT Bai Xiao-Chen XC Chang Lei-Fu LF Wu Yi Y Wang Hong-Wei HW Sui Sen-Fang SF

Proceedings of the National Academy of Sciences of the United States of America 20090302 12

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 m ...[more]

PMID: 19255437

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