Affiliation: | 1. Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15261;2. Department of Pathology, University of Utah Medical School, Salt Lake City, Utah 84132;3. Laboratoire de Microscopie Electronique, Institut de Biologie Structurale J.-P. Ebel, UMR 5075, CEA-CNRS-UJF, 38027 Grenoble, France |