Toxic component of a type II toxin-antitoxin (TA) system (PubMed:27672196). Acts as an RNase (Probable). Its toxic effect is neutralized by cognate antitoxin VapB2 but not by non-cognate antitoxin VapB1 (PubMed:27672196). Probably forms a complex with cognate antitoxin VapB2. Belongs to the PINc/VapC protein family.