InterPro : IPR020859

Name  ROC GTPase Short Name  ROC_GTPase
Type  Domain Description  Small GTPases form an independent superfamily within the larger class ofregulatory GTP hydrolases. This superfamily contains proteins that control avast number of important processes and possess a common, structurallypreserved GTP-binding domain [], []. Sequence comparisons of small G proteinsfrom various species have revealed that they are conserved in primarystructures 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), sixbeta-strands (B1-B6) and five polypeptide loops (G1-G5). A structuralcomparison of the GTP- and GDP-bound form, allows one to distinguish twofunctional loop regions: switch I and switch II that surround thegamma-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 ofthe phosphate groups. The G3 loop provides residues for Mg(2+) and phosphatebinding and is located at the N terminus of the A2 helix. The G1 and G3 loopsare sequentially similar to Walker A and Walker B boxes that are found inother nucleotide binding motifs. The G2 loop connects the A1 helix and the B2strand and contains a conserved Thr residue responsible for Mg(2+) binding.The guanine base is recognised by the G4 and G5 loops. The consensus sequenceNKXD of the G4 loop contains Lys and Asp residues directly interacting withthe nucleotide. Part of the G5 loop located between B6 and A5 acts as arecognition site for the guanine base [].The small GTPase superfamily can be divided in 8 different families:Arf small GTPases. GTP-binding proteins involved in protein trafficking bymodulating vesicle budding and un-coating within the Golgi apparatusRan small GTPases. GTP-binding proteins involved in nucleocytoplasmictransport. Required for the import of proteins into the nucleus and alsofor RNA exportRab small GTPases. GTP-binding proteins involved in vesicular traffic.Rho small GTPases. GTP-binding proteins that control cytoskeletonreorganisationRas small GTPases. GTP-binding proteins involved in signaling pathwaysSar1 small GTPases. Small GTPase component of the coat protein complex II(COPII) which promotes the formation of transport vesicles from theendoplasmic reticulum (ER)Mitochondrial Rho (Miro). Small GTPase domain found in mitochondrialproteins involved in mitochondrial traffickingRoc small GTPases domain. Small GTPase domain always found associated withthe COR domain.This entry represents the Roc small GTPase domain.

Sequence Features

GO Displayer


InterPro protein domain ID --> Contigs



0 Child Features

1 Contains

Id Name Short Name Type
IPR013684 Mitochondrial Rho-like MIRO-like Domain

1 Found In

Id Name Short Name Type
IPR001806 Small GTPase superfamily Small_GTPase Family

0 Parent Features

5 Publications

First Author Title Year Journal Volume Pages
Bourne HR The GTPase superfamily: conserved structure and molecular mechanism. 1991 Nature 349 117-27
Valencia A The ras protein family: evolutionary tree and role of conserved amino acids. 1991 Biochemistry 30 4637-48
Paduch M Structure of small G proteins and their regulators. 2001 Acta Biochim Pol 48 829-50
Pai EF Refined crystal structure of the triphosphate conformation of H-ras p21 at 1.35 A resolution: implications for the mechanism of GTP hydrolysis. 1990 EMBO J 9 2351-9
Bourne HR The GTPase superfamily: a conserved switch for diverse cell functions. 1990 Nature 348 125-32

To cite PlanMine, please refer to the following publication:

Rozanski, A., Moon, H., Brandl, H., Martín-Durán, J. M., Grohme, M., Hüttner, K., Bartscherer, K., Henry, I., & Rink, J. C.
PlanMine 3.0—improvements to a mineable resource of flatworm biology and biodiversity
Nucleic Acids Research, gky1070. doi:10.1093/nar/gky1070 (2018)