Biochemistry 2008, 47, 6583–6589
6583
Regulation of Protein Function: Crystal Packing Interfaces and Conformational Dimerization†,‡ Peter B. Crowley,*,§ Pedro M. Matias,| Hualing Mi,⊥ Susan J. Firbank,# Mark J. Banfield,# and Christopher Dennison# UCD School of Biomolecular and Biomedical Science, Conway Institute, UniVersity College Dublin, Belfield, Dublin 4, Ireland, Instituto de Tecnologia Quı´mica e Biolo´gica, UniVersidade NoVa de Lisboa, AV. Da Repu´blica, Apartado 127, 2781 901 Oeiras, Portugal, National Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China, and Institute for Cell and Molecular Biosciences, Medical School, Newcastle UniVersity, Newcastle upon Tyne NE2 4HH, U.K. ReceiVed January 22, 2008; ReVised Manuscript ReceiVed April 18, 2008
ABSTRACT:
The accepted view of interprotein electron transport involves molecules diffusing between donor and acceptor redox sites. An emerging alternative hypothesis is that efficient long-range electron transport can be achieved through proteins arranged in supramolecular assemblies. In this study, we have investigated the crystal packing interfaces in three crystal forms of plastocyanin, an integral component of the photosynthetic electron transport chain, and discuss their potential relevance to in vivo supramolecular assemblies. Symmetry-related protein chains within these crystals have Cu-Cu separations of
