Antitoxin component of a type II toxin-antitoxin (TA) system that counteracts the effect of the HigB-2 toxin. Binds to its own promoter and regulates transcription of the higB-2/higA-2 operon. Induced by amino acid starvation and the protein synthesis inhibitor chloramphenicol. HigB-2/HigA-2 has been shown to stabilize plasmids very efficiently in E.coli.