3H1C CRYSTAL STRUCTURE OF POLYNUCLEOTIDE PHOSPHORYLASE (PNPASE) CORE BOUND TO RNASE E AND TUNGSTATE TRANSFERASE, POLYNUCLEOTIDE PHOSPHORYLASE, RNA TURNOVER, CYTOPLASM, NUCLEOTIDYLTRANSFERASE, RNA-BINDING, STRESS RESPONSE, ENDONUCLEASE, HYDROLASE, NUCLEASE