Protein transport. Probably involved in vesicular traffic (By similarity). GTP + H2O = GDP + H(+) + phosphate (Microbial infection) Phosphocholinated at Ser-76 by L.pneumophila AnkX, leading to displace GDP dissociation inhibitors (GDI) (PubMed:21822290). Both GDP-bound and GTP-bound forms can be phosphocholinated. Dephosphocholinated by L.pneumophila Lem3, restoring accessibility to L.pneumophila GTPase effector LepB (PubMed:22158903). (Microbial infection) Glycosylated by S.typhimurium protein Ssek3: arginine GlcNAcylation prevents GTPase activity, thereby disrupting vesicular protein transport from the endoplasmic reticulum (ER) to the Golgi compartment. Belongs to the small GTPase superfamily. Rab family. Could be the product of a pseudogene.