| Primary Identifier | IPR010796 | Type | Family |
| Short Name | C2_B9-type_dom |
| description | The C2 domain is one of the most prevalent eukaryotic lipid-binding domains deployed in diverse functional contexts. Distinct versions of the C2 domain have been recognized, the classical C2, the PI3K-type, the tensin-type, the B9-type, the DOCK-type, the NT-type and the Aida-type. Despite their limited sequence similarity, all C2 domains contain at their core a compact β-sandwich composed of two four-stranded β-sheets with highly variable inter-strand regions that might contain one or more α-helices. One feature that is highly conserved in the C2 domains is the pair of hydrophobic residues on the upper part of the β-sheet, which are involved in imparting a curvature of the sheet that allows formation of a concave ligand-binding area [].This entry represents a family of B9-type C2 domain containing proteins, found in ciliary basal body associated proteins. Although its specific function is unknown, a cilia-specific role has been suggested for the poorly characterised B9-type C2 domain [, , ].Some proteins known to contain a B9-type C2 domain are listed below:Mammalian Tectonic-like complex member MKS1 (also known as Meckel syndrome 1 , MKS1). The tectonic-like complex is localised at the transition zone of primary cilia and acts as a barrier that prevents diffusion of transmembrane proteins between the cilia and plasma membranes. It is involved in centrosome migration to the apical cell surface during early ciliogenesis [, , ]. The homologue in Drosophila melanogaster is required for ciliary structure and function [, ]. Mammalian proteins B9D1 and B9D2. B9D1 is required for ciliogenesis and sonic hedgehog/SHH signaling [, ]. |
