Toxic component of a type II toxin-antitoxin (TA) system. A tRNA-(fMet) endonuclease, it cleaves both charged and uncharged tRNA-(fMet) between positions 38 and 39 at the anticodon stem-loop boundary. Does not cleave tRNA(Met), tRNA(Arg2), tRNA(His), tRNA(Leu), tRNA(Phe) tRNA(Thr1), tRNA(Tyr) or tRNA(Val). Overexpression in E.coli inhibits translation, leads to loss of cell growth and degradation of tRNA(fMet); these effects are neutralized by expression of cognate antitoxin VapB. The VapB/VapC complex probably regulates transcription of its own promoter. Ectopic overexpression in E.coli induces the YoeB toxin, but this is not the cause of VapC toxicity. Inhibited by EDTA. Forms a hetero-octamer (4 VapB and 4 VapC) complex with antitoxin VapB. The complex binds 2 different sites in the vapBC promoter, probably via VapB dimerization. Degradation of tRNA(fMet) is induced by chloramphenicol treatment, suggesting the antitoxin is unstable. Belongs to the PINc/VapC protein family.