Figure 2.

Cross-linking of aI221C-substituted membranes in varying combinations with second Cys in subunit c. SDS-solubilized membranes were electrophoresed under nonreducing condition before immunoblotting. The blot was first probed with antiserum against subunit c. The blot was then stripped of bound antibodies by submerging it in a buffer containing 62.5 mM Tris⋅HCl (pH 6.8), 2% SDS, and 100 mM 2-mercaptoethanol for 30 min at 50°C and reprobed with antiserum against subunit a. The bands marked IA* are immunoblotting artifacts. Wild-type membranes are from pDF163- (uncBEFH⁺) transformed strain JWP109 (ΔuncB–H). Deletion membranes are from strain JWP109 (ΔuncB–H).