GTPase-activator protein for Ras-like GTPase
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| GTPase-activator protein for Ras-like GTPase | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||||
| Symbol | RasGAP | ||||||||||
| Pfam | PF00616 | ||||||||||
| InterPro | IPR001936 | ||||||||||
| SMART | RasGAP | ||||||||||
| SCOP2 | 1wer / SCOPe / SUPFAM | ||||||||||
| CDD | cd04519 | ||||||||||
| |||||||||||
GTPase-activator protein for Ras-like GTPase is a family of evolutionarily related proteins. Ras proteins are membrane-associated molecular switches that bind GTP and GDP and slowly hydrolyze GTP to GDP.[1] This intrinsic GTPase activity of ras is stimulated by a family of proteins collectively known as 'GAP' or GTPase-activating proteins.[2][3] As it is the GTP bound form of ras which is active, these proteins are said to be down-regulators of ras.
The Ras GTPase-activating proteins are quite large (from 765 residues for sar1 to 3079 residues for IRA2) but share only a limited (about 250 residues) region of sequence similarity, referred to as the 'catalytic domain' or rasGAP domain.
Note: There are distinctly different GAPs for the rap and rho/rac subfamilies of ras-like proteins (reviewed in reference[4]) that do not share sequence similarity with ras GAPs.
