MLDKTRLRIAMQKSGRLSDESQELLSRCGIKINLQQQRLIAFAENMPIDILRVRDDDIPGLVMDGVVDLGIIGENVLEEELLNRRAQGDDPRYFTLRRLDFGGCRLSLAAPLDAEYTGPQCLQDTRIATSYPHILKQYLDKQGVRFKSCLLNGSVEVAPRAGLADAICDLVSTGATLEANGLREVEVIYRSKACLIQRDGEMSVDKQQLIDRLMTRIQGVIQARESKYIMMHAPSERLDEIITLLPGAERPTILPLAGDKSRVAMHMVSSETLFWETMEKLKALGASSILVLPIEKMME HIS1_YERPS hisG 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 (By similarity). 299 ATP phosphoribosyltransferase YPTB1562