1. School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
2. Leicester Institute of Structural and Chemical Biology and School of Chemistry, University of Leicester, Leicester, LE1 7RH, UK
3. Department of Molecular and Cell Biology, University of Leicester, Leicester, LE1 7RH, UK
4. Department of Molecular Medicine, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA