ATP switch model

MOSFET switching circuit (switch model, ATP-Draw, GUI). 

Fig. 5. The open (inactive) and closed (active) conformations of the adenylyl cyclase catalytic domains bound to GocGTPyS. Helices are shown as cylinders and [j strands as ribbons. The C2 domains of the two mAC molecules are superimposed. The open state of mAC, which was crystallized in the absence of an ATP analogue, is colored gray (PDB ID, 1AZS) the closed state, colored blue, was crystallized with ATPaS bound to the AC catalytic site, shown as a stick model (1CJT). Forskolin is present in both complexes. Switch II of Gas is colored red. Note that binding of ATP is accompanied by segmental movement of residues in both domains toward the catalytic site.

Fig. 14-9 A model for the cyclic synthesis of ATP by ATP synthase coupled to conformation changes in the P subunits brought about by proton translocation through the F0 complex. ATP synthesis occurs in the tightly bound" (T) state, but the ATP can only be released from the open (O) state. The energy of the electrochemical gradient is used to switch the T to the O state. The third state, L, can bind ADP.

However, the model cannot be used from the ATP-Draw, because there is no input column for the OPEN/GLOSE signal. The switch and the diode have to be separately entered. In this case, the switch and the diode are required to have their own on-resistance, because the EMTP cannot handle parallely connected switches. 

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