1 Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK. kevin.whitley@newcastle.ac.uk.
2 Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK.
3 School of Life Sciences, University of Warwick, Coventry, UK.
4 Department of Chemistry, University of Warwick, Coventry, UK.
5 School of Life Sciences, University of Warwick, Coventry, UK. seamus.holden@warwick.ac.uk.