1. Departamento de Química, CQFB, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2825-114 Caparica, Portugal, Architecture et Fonction des Macromolécules Biologiques, URA 9039, CNRS, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France, Laboratory of Protein Biochemistry and Protein Engineering, University of Gent, K.L. Ledeganckstraat 35, 9000 Gent, Belgium, Department of Biochemistry and Molecular Biology, Mayo Clinic Foundation, Rochester, Minnesota 55905, and Laboratoire...