SIGNALING PROTEIN, RESPONSE REGULATOR, RECEIVER DOMAIN, BEF3, TWO-COMPONENT SIGNAL TRANSDUCTION, CHEMOTAXIS, CYTOPLASM, FLAGELLAR ROTATION, MAGNESIUM, METAL-BINDING, PHOSPHOPROTEIN, TWO- COMPONENT REGULATORY SYSTEM CRYSTAL STRUCTURE OF CHEY TRIPLE MUTANT F14E, N59R, E89H COMPLEXED WITH BEF3- AND MN2+ 3FFX