[1] Univ Michigan, Program Chem Biol, Ann Arbor, MI 48109 USA
[2] Univ Michigan, Dept Chem, Ann Arbor, MI 48109 USA
[3] Univ Michigan, Dept Biol Chem, Ann Arbor, MI 48109 USA
[4] Univ Michigan, Life Sci Inst, Ann Arbor, MI 48109 USA
[5] Univ Calif San Francisco, Dept Pharmaceut Chem, San Francisco, CA 94158 USA