[1] Rutgers State Univ, Dept Chem & Chem Biol, Ctr Integrat Prote Res, Piscataway, NJ 08854 USA
[2] Cambridge Crystallog Data Ctr, Cambridge CB2 1EZ, England
[3] Scripps Res Inst, Dept Integrat Struct & Computat Biol, La Jolla, CA 92037 USA
[4] MRC, Mol Biol Lab, Cambridge CB2 0QH, England
[5] Univ Basel, Biozentrum, CH-4056 Basel, Switzerland
[6] SIB Swiss Inst Bioinformat, Basel, Switzerland
[7] Univ Virginia, Dept Mol Physiol & Biol Phys, Charlottesville, VA 22908 USA