[1] European Bioinformat Inst EMBL EBI, European Mol Biol Lab, Cambridge, England
[2] European Mol Biol Lab, Struct & Computat Biol Unit, D-69012 Heidelberg, Germany
[3] Max Delbruck Ctr Mol Med, Berlin, Germany
[4] Univ Calif San Francisco, Dept Cellular & Mol Pharmacol, San Francisco, CA 94143 USA
[5] Calif Inst Quantitat Biosci, San Francisco, CA USA
[6] J David Gladstone Inst, San Francisco, CA USA