1. Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
2. Molecular and Cellular Biology Ph.D. Program, University of Washington, Seattle, Washington, USA
3. Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
4. BD Biosciences, Seattle, Washington, USA
5. Division of Science and Mathematics, University of Minnesota, Morris, Minnesota, USA
6. Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom