Probable toxic component of a putative type VII toxin-antitoxin (TA) system, probably an RNase. Probably neutralized by cognate antitoxin MA_1295. Neutralization may be due to AMPylation by MA_1295. Homodimer, probably forms a complex with cognate antitoxin MA_1295. Modified by cognate antitoxin MA_1295; probably at least 2 successive AMPylation events occur on Tyr-82. Belongs to the HepT RNase toxin family.