Introduction - This script shows the structure of cytochrome oxidase, the terminal electron carrier [Based on 1occ.pdb - T.Tsukihara, H.Aoyama, E.Yamashita, T.Tomizaki, H.Yamaguchi, K.Shinzawa-Itoh, R.Nakashima, R.Yaono, S.Yoshikawa, Science 272 1136(1996)]. This is a large file and takes a few seconds to load - please be patient.
Cytochrome oxidase is a membrane bound dimer. This view shows the transmembrane helices and the probable location of the dimer in the membrane. The enzyme causes proton pumping from the matrix to the cytosol.
This is a single catalytic subunit.
One possible proton channel is shown. The channel contains a hydrogen-bonded water network that spans the membrane and through which a proton could move across the membrane. The channel also includes the heme group involved in electron transfer.