2JK1 CRYSTAL STRUCTURE OF THE WILD-TYPE HUPR RECEIVER DOMAIN DNA-BINDING, NUCLEOTIDE-BINDING, TRANSCRIPTION REGULATION, BERYLLIUM FLUORIDE PHOSPHORYLATION MIMIC, HUPR, ACTIVATOR, CYTOPLASM, ATP-BINDING, TWO-COMPONENT REGULATORY SYSTEM, TRANSCRIPTION, PHOSPHOPROTEIN, RESPONSE REGULATOR