Fig. 6.

How conformational changes in UreG during the GTP hydrolysis/binding cycle facilitate urease maturation. GTP binding induces conformational changes in UreG that destabilize the UreG₂F₂H₂ complex, causing UreG to dissociate from the complex and form the UreE₂G₂ complex with the nickel-charged UreE dimer. After receiving its nickel within the UreE₂G₂ complex, the nickel-charged UreG dimer is recruited to form the activation complex with apourease and UreF₂H₂. GTP hydrolysis induces conformational changes in the CPH motif of UreG, disrupting the square-planar coordination by Cys66/His68, and, hence, promotes release of the nickel ion for urease maturation. UreG, now in its GDP-bound state, prefers to form the UreG₂F₂H₂ complex, which is now ready to receive its nickel from UreE₂/Ni for another round of urease maturation.