CRYSTAL STRUCTURE OF THE PROBABLE 3-DHS DEHYDRATASE ASBF INVOLVED IN THE PETROBACTIN SYNTHESIS FROM BACILLUS ANTHRACIS 3DX5 LYASE, BETA-ALPHA BARREL, PETROBACTIN SYNTHESIS, ASB LOCUS, STRUCTURAL GENOMICS, PSI-2, PROTEIN STRUCTURE INITIATIVE, MIDWEST CENTER FOR STRUCTURAL GENOMICS, MCSG, UNKNOWN FUNCTION