1. Department of Cell Biology, SR11, The Scripps Research Institute, 10550 North Torrey Pines Road, 92037, La Jolla, CA, USA
2. Biosciences Division, Argonne Laboratory, Argonne, Illinois, USA
3. Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
4. Department of Microbiology, University of Illinois at Urbana-Champaign, Champaign, Illinois, USA
5. Diversa, Inc., San Diego, California, USA