The side chains Thr254, His354, and Arg399 of subunit A stabilize the molecule while FAD oxidizes and carries the electrons to the first of the iron-sulfur clusters, .
As cadeas laterais de Thr254, His354, e Arg399 da subunidade A estabiliza a molécula mentres que o FAD oxida e transporta os electróns ao primeiro cluster de ferro-xofre, o .