3C30 SIGNALING PROTEIN, TRANSFERASE, 2-COMPONENT SYSTEM, QUORUM SENSING, HISTIDINE KINASE, HYDROLASE, INNER MEMBRANE, MEMBRANE, PHOSPHOPROTEIN, PROTEIN PHOSPHATASE, TRANSMEMBRANE, TWO- COMPONENT REGULATORY SYSTEM CRYSTAL STRUCTURE OF THE VIBRIO CHOLERAE LUXQ PERIPLASMIC DOMAIN (SEMET)