Involved in metal homeostasis. Has GTPase activity. Binds several Zn(2+) ions in vitro. GTPase activity is enhanced by Zn(2+) binding. kcat is 0.19 min(-1). kcat is 0.33 min(-1) in the presence of Ni(2+). kcat is 0.32 min(-1) in the presence of Zn(2+). Oligomerizes in the presence of Zn(2+). Deletion of the gene increases the sensitivity of E.coli to the metal chelator EDTA and sensitivity to cadmium. Belongs to the SIMIBI class G3E GTPase family. CobW subfamily.