Domain

Phosphatidylinositol 3-kinase Ras-binding (PI3K RBD) domain (IPR000341)

Short name: PI3K_Ras-bd_dom

Domain relationships

None.

Description

Phosphatidylinositol 3-kinases (PI3Ks) are lipid kinases that phosphorylate 4,5-bisphonate (PI(4,5) P2 or PIP2) at the 3-position of the inositol ring, and thus generate phosphatidylinositol 3,4,5-trisphosphate (PIP3), which, in turns, initiates a vast array of signaling events. PI3Ks can be grouped into three classes based on their domain organisation. Class I PI3Ks are heterodimers consisting of a p110 catalytic subunit and a regulatory subunit of either the p85 type (associated with the class IA p110 isoforms p110alpha, p110beta or p110delta) or the p101 type (associated with the class IB p110 isoform p110gamma). Common to all catalytic subunits are an N-terminal adaptor-binding domain (ABD) that binds to p85, a Ras- binding domain (RBD), a putative membrane-binding domain (C2), a helical domain of unknown function, and a kinase catalytic domain. Class II PI3Ks lack the ABD domain and are distinguished by a carboxy terminal C2 domain. Class III enzymes lack the ABD and RBD domains [PMID: 17626883, PMID: 18079394, PMID: 20081827, PMID: 10580505].

PI3K RBD is a small globular domain of about 100 residues in length with an alpha/beta-sandwich topology. The PI3K RBD domain consists of a five-stranded mixed beta-sheet flanked by two alpha-helices [PMID: 17626883, PMID: 18079394, PMID: 20081827, PMID: 10580505].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE profiles
SMART
Pfam