An essential GTPase which binds GTP, GDP and possibly (p)ppGpp with moderate affinity, with high nucleotide exchange rates and a fairly low GTP hydrolysis rate. Plays a role in control of the cell cycle, stress response, ribosome biogenesis and in those bacteria that undergo differentiation, in morphogenesis control. Binds GDP with a dissociation constant of 1.7 uM and GTP with a dissociation constant of 6.5 uM. Monomer (By similarity). Binds RluD (AC P65836) as well as the 30S ribosomal subunit protein S9 (PubMed:17905831). Belongs to the TRAFAC class OBG-HflX-like GTPase superfamily. OBG GTPase family.