3KGY CRYSTAL STRUCTURE OF PUTATIVE DIHYDROFOLATE REDUCTASE (YP_001636057.1) FROM CHLOROFLEXUS AURANTIACUS J-10-FL AT 1.50 A RESOLUTION OXIDOREDUCTASE, PUTATIVE DIHYDROFOLATE REDUCTASE, STRUCTURAL GENOMICS, JOINT CENTER FOR STRUCTURAL GENOMICS, JCSG, PROTEIN STRUCTURE INITIATIVE, PSI-2