Catalyzes the condensation of ATP and 5-phosphoribose 1-diphosphate to form N'-(5'-phosphoribosyl)-ATP (PR-ATP). Has a crucial role in the pathway because the rate of histidine biosynthesis seems to be controlled primarily by regulation of HisG enzymatic activity. 1-(5-phospho-beta-D-ribosyl)-ATP + diphosphate = 5-phospho-alpha-D-ribose 1-diphosphate + ATP Amino-acid biosynthesis; L-histidine biosynthesis; L-histidine from 5-phospho-alpha-D-ribose 1-diphosphate: step 1/9. Heteromultimer composed of HisG and HisZ subunits. Lacks the C-terminal regulatory region which is replaced by HisZ. Belongs to the ATP phosphoribosyltransferase family. Short subfamily.