Figure 6 - full size

Figure 6.
Figure 6. Signal Transduction Model
In the model, the signal reaches the catalytic core of the HK via helix α1 rotation. This rotation modifies DHp packing and the position of the associated CA domain. The latter domain either approaches the phosphoacceptor His, triggering the autokinase reaction (center), or moves away to generate the appropriate docking surfaces for either the interaction with nonphosphorylated RR, promoting phosphotransfer (right), or the interaction with the P vert, similar RR, promoting dephosphorylation (left).