1. Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
2. Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA.
3. Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
4. Cleveland BioLabs Inc., Buffalo, NY 14203, USA.
5. Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.