Structural highlights
Function
SECB_ECOLI One of the proteins required for the normal export of some preproteins out of the cell cytoplasm. It is a molecular chaperone that binds to a subset of precursor proteins, maintaining them in a translocation-competent state. It also specifically binds to its receptor SecA. Its substrates include AmpC, DegP, FhuA, FkpA, GBP, LamB, MalE (MBP), OmpA, OmpF, OmpT, OmpX, OppA, PhoE, TolB, TolC, YbgF, YcgK, YgiW and YncE.[HAMAP-Rule:MF_00821]
Publication Abstract from PubMed
Molecular chaperones act on non-native proteins in the cell to prevent their aggregation, premature folding or misfolding. Different chaperones often exert distinct effects, such as acceleration or delay of folding, on client proteins via mechanisms that are poorly understood. Here we report the solution structure of SecB, a chaperone that exhibits strong antifolding activity, in complex with alkaline phosphatase and maltose-binding protein captured in their unfolded states. SecB uses long hydrophobic grooves that run around its disk-like shape to recognize and bind to multiple hydrophobic segments across the length of non-native proteins. The multivalent binding mode results in proteins wrapping around SecB. This unique complex architecture alters the kinetics of protein binding to SecB and confers strong antifolding activity on the chaperone. The data show how the different architectures of chaperones result in distinct binding modes with non-native proteins that ultimately define the activity of the chaperone.
Structural basis for the antifolding activity of a molecular chaperone.,Huang C, Rossi P, Saio T, Kalodimos CG Nature. 2016 Aug 8. doi: 10.1038/nature18965. PMID:27501151[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Huang C, Rossi P, Saio T, Kalodimos CG. Structural basis for the antifolding activity of a molecular chaperone. Nature. 2016 Aug 8. doi: 10.1038/nature18965. PMID:27501151 doi:http://dx.doi.org/10.1038/nature18965
