Victoria Yankovskaya,1*
Rob Horsefield,2*
Susanna Törnroth,3*
César Luna-Chavez,14
Hideto Miyoshi,5
Christophe Léger,6
Bernadette Byrne,2
Gary Cecchini,14§
So Iwata237§
The structure of Escherichia coli
succinate dehydrogenase (SQR), analogous to the mitochondrial
respiratory complex II, has been determined, revealing the electron
transport pathway from the electron donor, succinate, to the terminal
electron acceptor, ubiquinone. It was found that the SQR redox centers
are arranged in a manner that aids the prevention of reactive oxygen
species (ROS) formation at the flavin adenine dinucleotide. This is
likely to be the main reason SQR is expressed during aerobic
respiration rather than the related enzyme fumarate reductase, which
produces high levels of ROS. Furthermore, symptoms of genetic disorders associated with mitochondrial SQR mutations may be a result of ROS
formation resulting from impaired electron transport in the enzyme.
1 Molecular Biology Division, VA Medical
Center, San Francisco, CA 94121, USA.
2 Department
of Biological Sciences, Imperial College London, London SW7 2AY, UK.
3 Department of Biochemistry, Uppsala University,
BMC Box 576, S-75123 Uppsala, Sweden.
4 Department
of Biochemistry and Biophysics, University of California, San
Francisco, CA 94143, USA.
5 Division of Applied Life
Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku,
Kyoto 606-8502, Japan.
6 Inorganic Chemistry
Laboratory, Oxford University, South Parks Road, Oxford OX1 3QR, UK.
7 Division of Biomedical Sciences, Imperial College
London, London SW7 2AZ, UK.
*
These authors contributed equally to this work.
Present address: Center for Biophysics and
Computational Biology, Department of Biophysics, University of Illinois
Urbana-Champaign, Urbana, IL 61801, USA.
Present address: BIP07-CNRS, 31, Chemin Joseph
Aiguier, 13402 Marseille, France.
§
To whom correspondence should be addressed. E-mail:
s.iwata{at}ic.ac.uk or ceccini{at}itsa.ucsf.edu
