Figure 1. Cross-linking of GltPh-K55C/A364C.
a, Cartoon representation of two substrate-bound GltPh protomers (PDB code 2NWX) viewed in the membrane plain. The third protomer and TM4 of the protomer on the right are removed for clarity. TMs 1 through 6 are coloured salmon and wheat; the carboxyl terminal cores are light blue; and the hairpins HP1 and HP2 are dark blue. Bound L-asp and Na+ are shown as sticks and purple spheres, respectively. Orange spheres correspond to the Cα atoms of residues 55 and 364. All molecular representations have been generated using Pymol46. b, SDS PAGE analysis of GltPh-K55C/A364C before and after incubation with 100 μM CuPhen for indicated periods of time. Detergent-solubilized purified GltPh-K55C/A364C (left) and unpurified transporter in crude E. coli membranes (right) were visualized by Coomassie staining and western blotting, respectively. c, Cross-linking of GltPh-K55C/A364C in the presence of 50 μM HgCl2. Samples were analyzed as in b.