2D7U LIGASE, STRUCTURAL GENOMICS, CONSERVED HYPOTHETICAL PROTEIN, NPPSFA, NATIONAL PROJECT ON PROTEIN STRUCTURAL AND FUNCTIONAL ANALYSES, RIKEN STRUCTURAL GENOMICS/PROTEOMICS INITIATIVE, RSGI CRYSTAL STRUCTURE OF HYPOTHETICAL ADENYLOSUCCINATE SYNTHETASE, PH0438 FROM PYROCOCCUS HORIKOSHII OT3