Video 2

Movie S2. Activation of hCBS by AdoMet. The movie models the progression of hCBS from its basal toward its activated state. The main loop (L191–202) delineating the entrance of the catalytic site is depicted in magenta. Upon activation, the Bateman module shifts away from the catalytic pocket of the complementary subunit toward its own protein core, and L191–202 becomes more flexible and opens up. Relaxation of the loops delineating the catalytic cavity facilitates the unrestricted access of substrates into the pyridoxal-5′-phosphate (PLP) cavity and allows for the higher catalytic turnover.