Figure S1.

Comparison of Double Membrane Crystals of SecYEG with and without Preprotein

Side view of the SecYEG map with (A) and without (B) bound preprotein (determined previously (Breyton et al., 2002), without the imposed non-crystallographic symmetry) and with one dimer fitted into the maps (color coding is as Figure 2). Both maps are at 8 Å in-plane resolution and contoured at 1.5 SD. The double-membrane crystals of SecYEG prepared in this study (A) are around 12 Å less thick compared to those determined previously (B), and the unit cell is slightly larger. This effect is independent of the presence of the peptide and is due to variation in the crystal packing.