[1] Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA
[2] Broad Inst Harvard, Howard Hughes Med Inst, Cambridge, MA 02142 USA
[3] MIT, Cambridge, MA 02142 USA
[4] Harvard Univ, Dept Chem & Chem Biol, Cambridge, MA 02138 USA
[5] Austrian Acad Sci, CeMM Res Ctr Mol Med, A-1090 Vienna, Austria
[6] Univ Oulu, Dept Med Biochem & Mol Biol, Bioctr Oulu, Oulu Ctr Cell Matrix Res, FIN-90014 Oulu, Finland
[7] Univ Oxford, Struct Genom Consortium, Headington OX3 7DQ, England
[8] Oxford Biomed Res Unit, NIHR, Botnar Res Ctr, Oxford OX3 7LD, England