Required for maturation of urease via the functional incorporation of the urease nickel metallocenter. Disruption of the ure1 gene cluster suggests that it protects brucellae during their passage through the stomach. The major route of infection in human brucellosis is oral. UreD, UreF and UreG form a complex that acts as a GTP-hydrolysis-dependent molecular chaperone, activating the urease apoprotein by helping to assemble the nickel containing metallocenter of UreC. The UreE protein probably delivers the nickel. Belongs to the UreD family.