1. School of Biochemistry, Faculty of Life Sciences, University of Bristol 1 Cell Biology Laboratories , , Bristol BS8 1TD , UK
2. Graduate School of Pharmaceutical Sciences, Kyoto University 3 Department of Physiological Chemistry , , Sakyo-ku, Kyoto 606-8501 , Japan
3. Institute of Structural and Molecular Biology 4 , Department of Biological Sciences , , London , WC1E 7HX, UK
4. Birkbeck, University of London 4 , Department of Biological Sciences , , London , WC1E 7HX, UK
5. Faculty of Life Sciences, University of Bristol 2 Proteomics Facility , , Bristol BS8 1TD , UK