1SG2

Crystal structure of the periplasmic chaperone Skp

Summary for 1SG2

• Entry DOI: 10.2210/pdb1sg2/pdb
• Descriptor: Seventeen Kilodalton Protein (2 entities in total)
• Functional Keywords: protein folding, outer membrane protein, molecular dipole, hydrophobic surface, chaperone
• Biological source: Escherichia coli
• Cellular location: Periplasm: P0AEU7
• Total number of polymer chains: 3
• Total formula weight: 51132.72

Authors

Korndorfer, I.P.,Dommel, M.K.,Skerra, A. (deposition date: 2004-02-23, release date: 2004-09-14, Last modification date: 2024-05-22)

Primary citation

Korndorfer, I.P.,Dommel, M.K.,Skerra, A.
Structure of the periplasmic chaperone Skp suggests functional similarity with cytosolic chaperones despite differing architecture.
Nat.Struct.Mol.Biol., 11:1015-1020, 2004

PubMed Abstract: The 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.

PubMed: 15361861
DOI: 10.1038/nsmb828

Experimental method

X-RAY DIFFRACTION (2.35 Å)