Institution: | 1. Department of Structural Biology,Stop 311, St.?Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105‐3678 (USA), Fax: (+1)?901‐595‐3168 http://www.stjude.org/zheng;2. Laboratoire de Biologie du Development, University Pierre et Marie Curie, 75005 Paris (France), Fax: (+33)?1‐4427‐3451 |