1sg2
From Proteopedia
Crystal structure of the periplasmic chaperone Skp
Structural highlights
FunctionSKP_ECOLI Molecular chaperone that interacts specifically with outer membrane proteins, thus maintaining the solubility of early folding intermediates during passage through the periplasm. Required for the efficient release of OmpA from the inner membrane, the maintenance of its solubility in the periplasm, and, in association with lipopolysaccharide (LPS), for the efficient folding and insertion of OmpA into the outer membrane.[1] [2] [3] [4] [5] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe 17-kDa protein (Skp) of Escherichia coli is a homotrimeric periplasmic chaperone for newly synthesized outer-membrane proteins. Here we present its X-ray structure at a resolution of 2.35 A. Three hairpin-shaped alpha-helical extensions reach out by approximately 60 A from a trimerization domain, which is composed of three intersubunit beta-sheets that wind around a central axis. The alpha-helical extensions approach each other at their distal turns, resulting in a fold that resembles a 'three-pronged grasping forceps'. The overall shape of Skp is reminiscent of the cytosolic chaperone prefoldin, although it is based on a radically different topology. The peculiar architecture, with apparent plasticity of the prongs and distinct electrostatic and hydrophobic surface properties, supports the recently proposed biochemical mechanism of this chaperone: formation of a Skp(3)-Omp complex protects the outer membrane protein from aggregation during passage through the bacterial periplasm. Structure of the periplasmic chaperone Skp suggests functional similarity with cytosolic chaperones despite differing architecture.,Korndorfer IP, Dommel MK, Skerra A Nat Struct Mol Biol. 2004 Oct;11(10):1015-20. Epub 2004 Sep 12. PMID:15361861[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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