CRYSTAL STRUCTURE OF 3-KETO-L-GULONATE-6-PHOSPHATE DECARBOXYLASE FROM VIBRIO CHOLERAE O1 BIOVAR EL TOR STR. N16961 BIOSYNTHETIC PROTEIN, 3-KETO-L-GULONATE-6-PHOSPHATE DECARBOXYLASE, ULAD, CSGID, NIAID, STRUCTURAL GENOMICS, NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES (NIAID), CENTER FOR STRUCTURAL GENOMICS OF INFECTIOUS DISEASES 3IEB