LIGASE, STRUCTURAL GENOMICS, D-ALANYL-LIPOTEICHOIC ACID BIOSYNTHESIS, PROTEIN STRUCTURE INITIATIVE, PSI-2, NEW YORK SGX RESEARCH CENTER FOR STRUCTURAL GENOMICS, NYSGXRC 3BMA CRYSTAL STRUCTURE OF D-ALANYL-LIPOTEICHOIC ACID SYNTHETASE FROM STREPTOCOCCUS PNEUMONIAE R6