Fig. 7
From: A unified evolutionary origin for the ubiquitous protein transporters SecY and YidC
Structural features unique to SecY which enable signal binding and substrate translocation. SecY is G. thermodenitrificans SecY/proOmpA (6itc). a Signal-binding and ribosome-binding sites on SecY H2/3, viewed laterally. b The substrate translocation channel, viewed from its extracytoplasmic side. Only H1-5 and h4h5 of SecY are shown. SecY is colour-coded by consensus element as in Fig. 4 (left), or rendered transparent and superimposed by the corresponding elements of archaeal YidC (M. jannaschii MJ0480, 5c8j), aligned to the SecY C-half (right)