LIGASE, COILED-COIL, HOMODIMER, AMINOACYL-TRNA SYNTHETASE, ATP- BINDING, CYTOPLASM, NUCLEOTIDE-BINDING, PROTEIN BIOSYNTHESIS, STRUCTURAL GENOMICS, NPPSFA, NATIONAL PROJECT ON PROTEIN STRUCTURAL AND FUNCTIONAL ANALYSES, RIKEN STRUCTURAL GENOMICS/PROTEOMICS INITIATIVE, RSGI 2ZR2 CRYSTAL STRUCTURE OF SERYL-TRNA SYNTHETASE FROM PYROCOCCUS HORIKOSHII COMPLEXED WITH ATP