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Protein Domain : IPR001806

Name  Small GTPase superfamily Short Name  Small_GTPase
Type  Family Description  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 [, ]. 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 [].Crystallographic analysis of various small G proteins revealed the presence of a 20 kDa catalytic domain that is unique for the whole superfamily [, ]. 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 [].The small GTPase superfamily can be divided into at least 8 different families, including:Arf small GTPases. GTP-binding proteins involved in protein trafficking by modulating vesicle budding and uncoating within the Golgi apparatus.Ran small GTPases. GTP-binding proteins involved in nucleocytoplasmic transport. Required for the import of proteins into the nucleus and also for RNA export.Rab small GTPases. GTP-binding proteins involved in vesicular traffic.Rho small GTPases. GTP-binding proteins that control cytoskeleton reorganisation.Ras small GTPases. GTP-binding proteins involved in signalling pathways.Sar1 small GTPases. Small GTPase component of the coat protein complex II (COPII) which promotes the formation of transport vesicles from the endoplasmic reticulum (ER).Mitochondrial Rho (Miro). Small GTPase domain found in mitochondrial proteins involved in mitochondrial trafficking.Roc small GTPases domain. Small GTPase domain always found associated with the COR domain.

Publication Counts Displayer

6 Child Features

DB identifier Name Short Name Type
IPR021181 Small GTPase superfamily, mitochondrial Rho Rho_GTPase_Mt Family
IPR003579 Small GTPase superfamily, Rab type Small_GTPase_Rab_type Family
IPR020849 Small GTPase superfamily, Ras type Small_GTPase_Ras Family
IPR003578 Small GTPase superfamily, Rho type Small_GTPase_Rho Family
IPR017231 Small GTPase superfamily, Tem1 Small_GTPase_Tem1 Family
IPR016433 Small GTPase superfamily, predicted GTP-binding protein MJ1339 Small_GTPase_MJ1339 Family

5 Contains

DB identifier Name Short Name Type
IPR013566 EF hand associated,type-1 EF_hand_assoc_1 Domain
IPR013567 EF hand associated, type-2 EF_hand_assoc_2 Domain
IPR020860 MIRO MIRO Domain
IPR013684 Mitochondrial Rho-like MIRO-like Domain
IPR020859 ROC GTPase ROC_GTPase Domain

2 Cross References

Identifier
Source . Name

Subject . Primary Identifier
PF00071 PFAM IPR001806
PR00449 PRINTS IPR001806

3 Data Sets

Name URL
Swiss-Prot data set http://ca.expasy.org/sprot
InterPro data set  
InterPro GO Annotation data set  

0 Found In

2 GO Annotation


Subject . Secondary Identifier

Subject . Name

Subject . Symbol

Ontology Term . Identifier

Ontology Term . Name
Small GTPase superfamily   GO:0005525 GTP binding
Small GTPase superfamily   GO:0007264 small GTPase mediated signal transduction

2 Ontology Annotations


Subject . Secondary Identifier

Subject . Name

Subject . Symbol

Ontology Term . Identifier

Ontology Term . Name
Small GTPase superfamily   GO:0005525 GTP binding
Small GTPase superfamily   GO:0007264 small GTPase mediated signal transduction

0 Parent Features

753 Proteins

DB identifier Primary Accession
Organism . Name
FBpp0111700 Q9VDJ9 Drosophila melanogaster
FBpp0072614 P40792 Drosophila melanogaster
FBpp0071030 Q9W3Q0 Drosophila melanogaster
FBpp0086392 Q7JMZ0 Drosophila melanogaster
FBpp0088870 A1Z7S3 Drosophila melanogaster
FBpp0088871 Q8T0G8 Drosophila melanogaster
FBpp0088872 A1Z7S1 Drosophila melanogaster
FBpp0076428 O18339 Drosophila melanogaster
FBpp0110426 Q7PLE8 Drosophila melanogaster
FBpp0083980 Q8IMX7 Drosophila melanogaster
FBpp0072086 O96692 Drosophila melanogaster
FBpp0070098 Q9W5G7 Drosophila melanogaster
FBpp0071419 Q8IRK9 Drosophila melanogaster
FBpp0074107 Q9VXA9 Drosophila melanogaster
FBpp0301154 P40793 Drosophila melanogaster
FBpp0071229 Q9W389 Drosophila melanogaster
FBpp0301227 Q9VM50 Drosophila melanogaster
FBpp0077029 O15971 Drosophila melanogaster
FBpp0081617 Q9VH66 Drosophila melanogaster
FBpp0088074 Q9V4L4 Drosophila melanogaster
FBpp0085498 A1Z6R7 Drosophila melanogaster
FBpp0309684 A8DYK6 Drosophila melanogaster
FBpp0072476 Q9W0N7 Drosophila melanogaster
FBpp0076640 Q9VS10 Drosophila melanogaster
FBpp0073068 P04388 Drosophila melanogaster
FBpp0074690 O18338 Drosophila melanogaster
FBpp0077843 Q9VPG7 Drosophila melanogaster
FBpp0073328 Q9VZ23 Drosophila melanogaster
FBpp0089130 P48148 Drosophila melanogaster
FBpp0070280 O76901 Drosophila melanogaster