CHAPERONE, ATP BINDING DOMAIN, HEAT SHOCK PROTEIN, STRUCTURAL GENOMICS, ATP-BINDING, NUCLEOTIDE BINDING, STRESS RESPONSE, STRUCTURAL GENOMICS CONSORTIUM, SGC, NUCLEOTIDE-BINDING 3L4I CRYSTAL STRUCTURE OF THE N-TERMINAL DOMAIN OF HSP70 (CGD2_20) FROM CRYPTOSPORIDIUM PARVUM IN COMPLEX WITH ADP AND INORGANIC PHOSPHATE