Figure 5.

Closure of space between PASA domain and SM domain in WT SIM1 during apo simulation. The structure is colored by domain (as per Figure 1A) and rendered in ribbons and licorice sticks for residues of interest. (A) SIM1 in its apo, unbound form is shown for the initial starting conformation. Call-out box shows a close-up of the PASA domain and SM domain, with a 38.4 Å gap where ARNT would occupy. (B) SIM1 in its apo, unbound form is shown after completion of >100 ns simulation. Call-out box shows a close-up of the same region, now approximately 26 Å closer. This closed conformation would preclude ARNT from binding.