Fig. 3.

CL1 and CL2 of TAP1 have distinct functions in peptide binding and translocation. Single-cysteine TAP1 mutants of CL1 (A) or CL2 (B) in complex with E602C(TAP2) were analyzed for peptide binding (gray bars) and transport (black bars). Peptide binding and transport were performed as described in the legend of Fig. 2. Specific peptide binding and transport of TAP1(Cys-less)/TAP2(E602C) was normalized to 100%. Data were collected from 3 independent experiments. The error bars represent the standard deviation. Equal amounts of TAP1 and TAP2 were confirmed by immunoblotting.