The low-spin heme of cytochrome c oxidase as the driving element of the proton-pumping process. - Tsukihara,T..; Shimokata,K..; Katayama,Y..; Shimada,H..; Muramoto,K..; Aoyama,H..; Mochizuki,M..; Shinzawa-Itoh,K..; Yamashita,E..; Yao,M..; Ishimura,Y..; Yoshikawa,S.. (Proceedings of the National Academy of Sciences of the USA, 2003)