Fig. 7.

Cross-linking of 2C8H and its F-G loop mutants in bacterial membranes. Based on the 2C8dH crystal structure, as shown in Fig. 1B, Trp-212 and Cys-225 and Arg-206 and Gly-228 in the F-G loop are the closest two pairs of residues. To determine whether the F-G loop forms a dimer interface, Cys was substituted for Trp-212 or for Arg-206 and Gly-228 in the C24S mutant of 2C8H, and the mutants were expressed in bacteria, and membranes were treated with (A) Cu²⁺-phenanthroline or (B) BMOE cross-linker. The proteins in the membranes were analyzed as described in the legend to Fig. 2. Asterisks denote the expected mobility of the 2C8H dimer. M.W., molecular weight.