A. The projection map of SecA 2D crystals with SecB, averaged from 3 images without symmetry imposed. The scale bar is 2.5 nm.
B. Merging of the original SecA crystal structure with SecA/SecB crystal structure. The white dashed contour is the projection map of SecA/SecB. The dark solid contour is the projection map of SecA alone. The projection maps were rotated and translated according to the cross-correlation calculation, and then merged together. The main different domain is indicated by dark arrow. The scale bar is 2.5 nm.
C. The putative diagram of SecB binding to SecA ring-like structure. SecB is indicated as a grey rhombus. The scale bar is 2.5 nm.