FIG. 4.

Chemical cross-linking reveals a CcoQ-CcoP interaction. CcoQ was in vitro synthesized as described in Fig. 1 and incubated with homo-bifunctional cross-linker DSS in the presence or absence of R. capsulatus wild-type membranes, grown aerobically on MPYE medium. Immunoprecipitations were performed with 150-μl in vitro reaction mixtures using protein A-Sepharose-coupled antibodies directed against CcoP and CcoN.