FIG. 1.

Cross-linking of complexes between cysteine variants of SecA and SecB. Cross-linking values were estimated as described in Materials and Methods. Values of 40% cross-linking or more are shown in purple if the cross-linking partner lies in the SecA amino-terminal region, in green if the partner is located in the SecA linker helix, and in red if the partner lies in the SecA helical scaffold domain. Values between 21% and 39% are black, and those less than 20% are indicated by “—.” Values between 16% and 20% are dark black dashes, and those less than 15% are light gray dashes. All values are the average of between 2 and 5 cross-linking experiments. The average number of cross-linking experiments used to calculate each percentage greater than 40 shown in the figure was 3.1 (41 values obtained from 129 cross-linking experiments).