FIGURE 2.

Deduced structure of KscA and attachment sites for TMR-maleimide. A, tested mutations are shown on a structure deduced from EPR measurements (Protein Data Bank code 1F6G). Two of four subunits are presented in this figure. Positions where a cysteine was introduced are indicated with a yellow circle. Dotted lines show membrane/solution interfaces. B, purified mutants were labeled with TMR-maleimide and reconstituted into liposomes. Proteins were analyzed by fluorography (Molecular Imager, Bio-Rad) after SDS-PAGE. The arrowhead indicates the KcsA monomer. Lane 1, wild type; lane 2, E71A; lane 3, G53C; lane 4, A132C.