Fig. 6. In vitro binding of CPC to R. The intact and truncated R proteins were translated in vitro, labeled with [³⁵S]methionine, incubated with or without the purified GST-CPC protein or with the GST protein, and adsorbed on glutathione-Sepharose. The Sepharose-bound proteins were analyzed by SDS-polyacrylamide gel electrophoresis. Lane 1: intact R protein before incubation; lane 2: N-terminal region of R (residues 1-312) before incubation; lane 3: C-terminal region of R (residues 372-525) before incubation; lane 4: intact R incubated with GST-CPC; lane 5: N-terminal region of R incubated with GST-CPC; lane 6: C-terminal region of R incubated with GST-CPC; lane 7: intact R incubated with GST; lane 8: N-terminal region of R incubated with GST; lane 9: C-terminal region of R incubated with GST.