Figure 6.

Dominant mutant forms of BiP are unable to undergo an ATP-dependent conformational change. Either wild-type or dominant mutant BiP (as indicated) was preincubated with either ATP or ADP before the addition of proteinase K, as described in MATERIALS AND METHODS. The resulting cleavage products were resolved by SDS-PAGE and visualized by Coomassie brilliant blue staining. The filled arrow indicates the position of the ∼60-kDa fragment (corresponding to the ATPase domain and a portion of the C-terminal peptide-binding domain), and the open arrow indicates the position of the ∼45-kDa fragment (comprised primarily of the ATPase domain).