Antitoxin component of a type II toxin-antitoxin (TA) system that counteracts the effect of the HigB-1 toxin. Binds to its own promoter and regulates transcription of the higB-1/higA-1 operon. Induced by amino acid starvation. Induced by the protein synthesis inhibitors chloramphenicol, kanamycin and to a lesser extent by spectinomycin. HigB-1/HigA-1 has been shown to stabilize plasmids very efficiently in E.coli.