| | Cytochrome c6A is a funnel for thiol oxidation in the thylakoid lumenEdited by Richard Cogdell Received 2 March 2006; received in revised form 17 March 2006; accepted 20 March 2006. published online 27 March 2006. Abstract Cytochrome c6A is a dithio-cytochrome recently discovered in land plants and green algae, and believed to be derived from the well-known cytochrome c6. The function of cytochrome c6A is unclear. We propose that it catalyses the formation of disulphide bridges in thylakoid lumen proteins in a single-step disulphide exchange reaction, with subsequent transfer of the reducing equivalents to plastocyanin. The haem group of cytochrome c6A acts as an electron sink, allowing rapid resolution of a radical intermediate formed during reoxidation of cytochrome c6A. Our model is consistent with previously published data on mutant plants, and the likely evolution of the protein. a Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK b Department of Biology, University College London, London WC1E 6BT, United Kingdom  Corresponding author. Fax: +44 1223 333345.
PII: S0014-5793(06)00367-X doi:10.1016/j.febslet.2006.03.052 © 2006 Federation of European Biochemical Societies | |
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ABSTRACT
