View source for Biology:GTPase-activator protein for Ras-like GTPase

{{Short description|Protein family}}
{{Pfam_box 
| Symbol = RasGAP 
| Name = GTPase-activator protein for Ras-like GTPase 
| image = 
| width = 
| caption = 
| Pfam= PF00616
| InterPro= IPR001936
| SMART=  RasGAP
| Prosite =          
| SCOP = 1wer
| TCDB = 
| OPM family= 
| OPM protein= 
| CDD = cd04519
| PDB= 
{{PDB3|1nf1}}A:1256-1451 {{PDB3|1wer}} :769-942   {{PDB3|1wq1}}G:769-942   
}} 
'''GTPase-activator protein for Ras-like GTPase''' is a [[Biology:Protein family|family of evolutionarily related proteins]]. [[Biology:Ras subfamily|Ras]] proteins are membrane-associated molecular switches that bind [[Chemistry:Guanosine triphosphate|GTP]] and [[Chemistry:Guanosine diphosphate|GDP]] and slowly hydrolyze GTP to GDP.<ref name="PUB00004087">{{cite journal |vauthors=McCormick F, Bourne HR, Sanders DA |title=The GTPase superfamily: conserved structure and molecular mechanism |journal=Nature |volume=349 |issue=6305 |pages=117–127 |year=1991 |pmid=1898771 |doi=10.1038/349117a0|bibcode=1991Natur.349..117B |s2cid=4349901 }}</ref> This intrinsic [[Biology:GTPase|GTPase]] activity of ras is stimulated by a family of proteins collectively known as 'GAP' or GTPase-activating proteins.<ref name="PUB00000983">{{cite journal |vauthors=Wang Y, Riggs M, Rodgers L, Wigler M, Boguski M |title=sar1, a gene from Schizosaccharomyces pombe encoding a protein that regulates ras1 |journal=Cell Regul. |volume=2 |issue=6 |pages=453–465 |year=1991 |pmid=1883874 |pmc=361829 |doi=10.1091/mbc.2.6.453}}</ref><ref name="PUB00000726">{{cite journal |vauthors=Maruta H, Burgess AW |title=Regulation of the Ras signalling network |journal=BioEssays |volume=16 |issue=7 |pages=489–496 |year=1994 |pmid=7945277 |doi=10.1002/bies.950160708|s2cid=22850138 }}</ref> 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<ref name="PUB00004162">{{cite journal |vauthors=McCormick F, Boguski MS |title=Proteins regulating Ras and its relatives |journal=Nature |volume=366 |issue=6456 |pages=643–654 |year=1993 |pmid=8259209 |doi=10.1038/366643a0|bibcode=1993Natur.366..643B |s2cid=4338237 }}</ref>) that do not share sequence similarity with ras GAPs.

== Examples ==
Human genes encoding proteins containing this domain include:
* DAB2IP;
* GAPVD1;
* IQGAP1;    [[Biology:IQGAP2|IQGAP2]];    IQGAP3;
* [[Biology:Neurofibromin 1|NF1]];
* [[Biology:RAS p21 protein activator 1|RASA1]];     RASA2;     RASA3;     [[Biology:RASA4|RASA4]];     RASAL1;    RASAL2;
* [[Biology:SYNGAP1|SYNGAP1]];

== References ==
{{reflist}}

{{InterPro content|IPR001936}}

[[Category:Protein domains]]
[[Category:Protein families]]
[[Category:Membrane proteins]]



{{Sourceattribution|GTPase-activator protein for Ras-like GTPase}}