7.6.2.8 BtuCD transporter can be re-assembled from both prefolded and partly unfolded, urea denatured BtuC and BtuD subunits. The in vitro re-assembly leads to a BtuCD complex with the correct, native, BtuC and BtuD subunit stoichiometry. The highest rates of ATP hydrolysis are achieved for BtuCD re-assembled from partly unfolded subunits. This supports the idea of cooperative folding and assembly of the constituent protein subunits of the BtuCD transporter 7.6.2.8 liposome reconstitution of recombinant purified BtuCD 7.6.2.8 purified BtuCD-F complex is functionally reconstituted in liposomes 7.6.2.8 recombinant His-tagged protein ABCD4 protein solubilization and reconstitution in proteoliposomes