1. Institut Européen de Chimie et Biologie, UMR 5248 CBMN, CNRS-Université Bordeaux 1-ENITAB, IECB, 2 rue Robert Escarpit, 33607 Pessac, France, and Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1, Kurokami, Kumamoto 860-8555, Japan