Affiliation: | 1. Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720 (USA);2. Department of Molecular and Cellular Biology, University of California, Berkeley, Berkeley, CA 94720 (USA), Fax: (+1)?510‐643‐6791;3. Department of Chemistry, University of Munich, Butenandtstrasse 5‐13 (F4.086), 81377 Munich (Germany), Fax: (+49)?89‐2180‐77972 |