1. Department of Biochemistry, University of Wisconsin‐Madison, 433 Babcock Drive, Madison, WI 53706‐1544 (USA), Fax: (+1) 608‐262‐3453 http://www2.biochem.wisc.edu/raines
2. Department of Chemistry, University of Wisconsin‐Madison, 1101 University Avenue, Madison, WI 53706‐1322 (USA)