Involved in the biosynthesis of ADP-glucose, a building block required for the elongation reactions to produce glycogen. Catalyzes the reaction between ATP and alpha-D-glucose 1-phosphate (G1P) to produce pyrophosphate and ADP-Glc. alpha-D-glucose 1-phosphate + ATP + H(+) = ADP-alpha-D-glucose + diphosphate Activated by 3-phosphoglycerate and inhibited by phosphate. Glycan biosynthesis; glycogen biosynthesis. Homotetramer. Belongs to the bacterial/plant glucose-1-phosphate adenylyltransferase family.