Fig. 1.

(A) Gene-expression system used for production of the HTL, as described in Schulze et al. (6). (B) SDS/PAGE and negative-stain electron microscopy analysis of the purified HTL, as shown in Schulze et al. (6). (C) Model of structural organization of the HTL. YidC (PDB ID code 3BLC) and SecDF (PDB ID code 3AQP) are docked on the structure of SecYEG (PDB ID code 1RH5). The structure of the transmembrane portion of YidC is unknown. The arrow illustrates the proposed rotation of the SecD periplasmic domain. Figure kindly provided by Mike Carlson.