Figure 4 - full size

Figure 4.
Figure 4. Model for catalysis by class III nucleotidyl cyclases. The model for catalysis (bottom pathway) is based on the conformational changes observed with the sAC -substrate analog complexes (top). The arrows at 1 and 7 - 8 indicate the movements undergone by these protein parts. The individual catalytic states (open, intermediate and closed) are extrapolated from the different sAC structures presented in the text, with the protein conformation of the sAC -Rp-ATP S complex being a speculative approximate intermediate state.