Catalyzes the transfer of adenosine 5'-monophosphate (AMP) to Ser, Thr and Tyr residues of target proteins (AMPylation). Cannot use GTP, CTP or UTP as cosubstrate. AMPylates SucA at 'Thr-405' and GrxA on 'Tyr-13'. Regulates protein S-glutathionylation levels probably by AMPylation of deglutathionylation enzymes such as GrxA. Probably involved in redox homeostasis. ATP + L-tyrosyl-[protein] = diphosphate + O-(5'-adenylyl)-L-tyrosyl-[protein] ATP + L-threonyl-[protein] = 3-O-(5'-adenylyl)-L-threonyl-[protein] + diphosphate ATP + L-seryl-[protein] = 3-O-(5'-adenylyl)-L-seryl-[protein] + diphosphate Activated in reducing conditions. Reduction/oxidation of the intramolecular disulfide bond involving Cys-272 and Cys-476 regulates YdiU catalytic activity. Moderate decrease in global protein S-glutathionylation. Belongs to the SELO family.