2DZC LIGASE, BIOTIN BIOSYNTHESIS, DIMER, X-RAY DIFFRACTION, STRUCTURAL GENOMICS, NPPSFA, NATIONAL PROJECT ON PROTEIN STRUCTURAL AND FUNCTIONAL ANALYSES, RIKEN STRUCTURAL GENOMICS/PROTEOMICS INITIATIVE, RSGI CRYSTAL STRUCTURE OF BIOTIN PROTEIN LIGASE FROM PYROCOCCUS HORIKOSHII, MUTATION R48A