Figure 1.

Growth (function) of Cys-substituted mutants (A) and summary of a–c cross-linking results (B). (A) Cells were plated on succinate minimal medium and the colony size (mm) was measured after incubation at 37°C for 3 days as a measure of oxidative phosphorylation function. The chromosomal, wild-type control strain showed colonies of 2 mm after 3 days at 37°C. (B) Relative yield of a–c cross-linked dimer formed between Cys at the positions indicated. Membrane vesicles were treated with CuP at 10°C for 60 min. Relative yield of the a–c cross-link product: 0, none; −/+, ≤5%; +, 6–10%; ++, 11–20%; +++, 20–40%; ++++, >40%. 0* indicates Cys pair forming no cross-link at 10°C but significant cross-link (8%) at 20°C.