1. Département de Réponse et Dynamique Cellulaires, CEA-Grenoble, 38054 Grenoble, France, Chemistry Department, Tulane University, New Orleans, Louisiana 70118, Department of Chemistry and Center for Metalloenzyme Studies, University of Georgia, Athens, Georgia 30602, Département de Recherche Fondamentale sur la Matière Condensée, CEA-Grenoble, 38054 Grenoble, France, and Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213