Antitoxin component of an atypical type II toxin-antitoxin (TA) system. Unlike most type II TA systems, neutralizes the toxic activity of cognate toxin SocB by acting as an adapter to promote its degradation by ClpXP; degradation is dependent on the N-terminus of ClpX. Interacts with cognate toxin SocB and with ClpX. Induced by DNA damaging agent mitomycin C, part of the socA-socB operon. Essential, it cannot be deleted unless the downstream gene for cognate toxin socB is also deleted. In depletion experiments the half-life of SocB is 19 minutes in the absence of SocA and about 2 minutes in its presence.