TRANSPORT PROTEIN, ABC, TRANSPORTER, PERMEASE, DOMAIN, PORPHYROMONAS, GINGIVALIS, PSI, MCSG, STRUCTURAL GENOMICS, MIDWEST CENTER FOR STRUCTURAL GENOMICS, PROTEIN STRUCTURE INITIATIVE, CELL MEMBRANE, MEMBRANE, TRANSMEMBRANE THE CRYSTAL STRUCTURE OF A DOMAIN OF A PUTATIVE PERMEASE PROTEIN FROM PORPHYROMONAS GINGIVALIS TO 2A 3IS6