Fig. 5
From: Large conformational changes of a highly dynamic pre-protein binding domain in SecA
Model of the change in Förster resonance energy transfer (FRET) efficiencies of SecA in the presence or absence of adenosine triphosphate (ATP). FRET efficiencies were calculated in distances (numbers next to circles in nm). The relative probabilities of the distances are displayed colour-coded (right panel), with darker colours (purple/blue/cyan) representing lower probability. Brighter colours (yellow/orange/red) represent higher probabilities. The sizes of the circles are represented relative to the frequency of events, correlating to the integral of their Gauss curves. The addition of ATP to SecA 329–704 results in a conformational change where the pre-protein binding domain (PBD) moves closer to helical wing domain (HWD) (a, b). In the absence of ATP, the FRET data for SecA 329–427 indicate the existence of several different conformations with one major conformation where IRA2 idles to approach PBD (c). The movement of the PBD to HWD in SecA 329–427 is more prominent in the presence of ATP (d). A domain representation (e) summarises our interpretation
