Homologous Superfamily

Skp domain superfamily (IPR024930)

Short name: Skp_dom_sf

Overlapping entries


This superfamily represents the Skp (also known as OmpH) domain, named after the Skp protein which functions as a periplasmic chaperone for newly synthesised outer-membrane proteins [PMID: 15361861, PMID: 15304217]. Three hairpin-shaped alpha-helical extensions reach out by approximately 60 A from a trimerisation region, 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 forcep'. 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.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.