FIG. 5.

Molecular modeling of the regions subjected to cysteine scanning mutagenesis. The second periplasmic loop of the SecE protein and the first periplasmic loop of the SecY protein are depicted as antiparallel α-helices. The positions of the amino acids subjected to cysteine scanning are shown as numbers within circles. We have linked the amino acids at points sufficiently proximal to form disulfide bonds when replaced by cysteines.