The domain within your query sequence starts at position 1336 and ends at position 1491; the E-value for the Ras domain shown below is 2.8e-16.
KLMIVGNTGSGKTTLLQQLMKMKKPELGMQGATVGIDVRDWSIQIRGKRRKDLVLNVWDF AGREEFYSTHPHFMTQRALYLAVYDLSKGQAEVDAMKPWLFNIKARASSSPVILVGTHLD VSDEKQRKACISKITKELLNKRGFPTIRDYHFVNAT
|PFAM accession number:||PF00071|
|Interpro abstract (IPR001806):|
Small GTPases form an independent superfamily within the larger class of regulatory GTP hydrolases. This superfamily contains proteins that control a vast number of important processes and possess a common, structurally preserved GTP-binding domain [(PUBMED:2122258), (PUBMED:1898771)]. Sequence comparisons of small G proteins from various species have revealed that they are conserved in primary structures at the level of 30-55% similarity [(PUBMED:2029511)].
Crystallographic analysis of various small G proteins revealed the presence of a 20 kDa catalytic domain that is unique for the whole superfamily [(PUBMED:1898771), (PUBMED:2196171)]. The domain is built of five alpha helices (A1-A5), six beta-strands (B1-B6) and five polypeptide loops (G1-G5). A structural comparison of the GTP- and GDP-bound form, allows one to distinguish two functional loop regions: switch I and switch II that surround the gamma-phosphate group of the nucleotide. The G1 loop (also called the P-loop) that connects the B1 strand and the A1 helix is responsible for the binding of the phosphate groups. The G3 loop provides residues for Mg(2+) and phosphate binding and is located at the N terminus of the A2 helix. The G1 and G3 loops are sequentially similar to Walker A and Walker B boxes that are found in other nucleotide binding motifs. The G2 loop connects the A1 helix and the B2 strand and contains a conserved Thr residue responsible for Mg(2+) binding. The guanine base is recognised by the G4 and G5 loops. The consensus sequence NKXD of the G4 loop contains Lys and Asp residues directly interacting with the nucleotide. Part of the G5 loop located between B6 and A5 acts as a recognition site for the guanine base [(PUBMED:11995995)].
The small GTPase superfamily can be divided into at least 8 different families, including:
|GO process:||small GTPase mediated signal transduction (GO:0007264)|
|GO function:||GTP binding (GO:0005525)|