Probable toxic component of a type II toxin-antitoxin (TA) system. The cognate antitoxin is VapB5. Has limited RNase activity on substrates; activity is seen with a VapC5-VapB5 complex. Forms a complex with VapB5. Following 6 weeks of nutrient starvation. Was identified as a high-confidence drug target. Belongs to the PINc/VapC protein family.