Affiliation: | (1) Department of Biological Sciences, Stanford University, 94305 Stanford, CA, USA;(2) California Biotechnology, 2450 Bayshore Frontage Road, 94043 Mountain View, CA, USA;(3) Department of Plant Biology, Carnegie Institution of Washington, 94305 Stanford, CA, USA;(4) Present address: Abteilung Zellbiologie, Max Planck Institut für Biochemie, D-8033 Martinsried, Federal Republic of Germany |