1. School of Life SciencesUniversity of LincolnLincolnLN6 7TS UK
2. School of Life and Health SciencesAston UniversityBirminghamB4 7ET UK
3. Department of BiochemistryUniversity of OxfordSouth Parks RoadOxfordOX1 3QU UK
4. MRC Centre for Molecular Bacteriology and Infection, Department of Life SciencesImperial College LondonKensingtonLondonSW7 2DD UK
5. Centre for Molecular and Structural Biochemistry, School of Biological SciencesUniversity of East AngliaNorwichNR4 7TJ UK
6. Departamento de Bioquímica y Biología MolecularUniversidad de Córdoba, Edificio Severo Ochoa1a planta, Campus de RabanalesCórdoba14071 Spain