1. Department of Chemistry, Portland State University, Portland, Oregon, USA
2. Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA
3. Institute of General Microbiology, University of Kiel, Kiel, Germany
4. Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, USA
5. Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA
6. Department of Biology, Portland State University, Portland, Oregon, USA