Light, time and micro-organisms

Tony Crofts's mechanism for bifurcated electron transfer at the Qo site of cytochrome b-c1 complexes

Further information on the Cytochrome b-c complex site, and from The Crofts lab at the University of Illinois at Urbana-Champaign.

The mobile head of the iron sulfur protein (ISP) (red spacefilling model) of the complex moves between docking interfaces on cytochrome b (light blue) and cytochrome c1 (green), while the anchor (dark blue) remains stationery. Electron transfer occurs from QH2 at the cytochrome b interface, and to heme c1 at the cytochrome c1 interface, and the ISP moves back and forth between these sites as the enzyme turns over.

Crofts, A.R., Barquera, B., Gennis, R.B., Kuras, R., Guergova-Kuras, M. and Berry, E.A. (1998) Mechanistic aspects of the Qo-site of the bc1-complex as revealed by mutagenesis studies, and the crystallographic structure. Proceedings of the IXth. International Symposium on Phototrophic Prokaryotes, Vienna, Sept. 1997, (Peschek et al., eds.). In press. 
©Copyright 1996, Antony Crofts, University of Illinois at Urbana-Champaign,