FIG 3.

Disulfide bonds properly form between the SurA P1 domain and core module. (A) SurA disulfide tethers were designed using the disulfide database (DSDBASE) (28) and were depicted on the SurA crystal structure (PDB accession no. 1M5Y). The surA10 residue (S220) is represented by red spheres. In each mutant, the residues used for cysteine substitution are represented by black spheres and are boxed. (B) Whole-cell lysates were suspended in loading buffer with (+, left) or without (−, right) the reducing agent β-ME prior to SDS-PAGE and immunoblotting for the proteins indicated. MBP is shown as a control.