1. Division of Structural Biology, The Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK.
2. Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK.
3. Centre for Translational Therapeutics, University of Leicester, Henry Wellcome Laboratories for Structural Biology, Lancaster Road, Leicester LE1 9HN, UK.
4. Department of Biochemistry, University of Leicester, Henry Wellcome Laboratories for Structural Biology, Lancaster Road, Leicester LE1 9HN, UK.