1. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA.
2. National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA.
3. Division of Biology and Bioengineering, California Institute of Technology, Pasadena, CA 91125, USA.
4. Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, “Chemistry Meets Microbiology” Research Network, University of Vienna, 1090 Vienna, Austria.
5. Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA.