Antitoxin component of a type IV toxin-antitoxin (TA) system (PubMed:14594833, PubMed:22515815, PubMed:28257056). Antitoxin that counteracts the effect of its cognate toxin CbtA (YeeV) (PubMed:14594833, PubMed:22515815, PubMed:28257056). It does not bind to the toxin but instead binds to MreB and FtsZ (the toxin targets), enhancing their polymerization by forming higher-order bundles; it is probably retained in the MreB and FtsZ filament bundles (PubMed:22515815). The mechanism has been proposed to require intergenic DNA, in cis, between the cbeA (yeeU) and cbta (yeeV) genes (PubMed:14594833). The intergenic region was not found to be necessary in another study (PubMed:22515815). Also counteracts the morphological defects caused by overexpression of SulA and DicB on cell shape (PubMed:22515815). Also counteracts the effect of non-cognate toxins YfkI and YpjF (PubMed:28257056). Binds 1 Mg(2+) ion per subunit. Homodimer (Probable). Interacts with polymerized and monomeric MreB and polymerized FtsZ (PubMed:22515815). Expressed in mid-log phase at considerably lower levels than antitoxin relB. Single deletion has no effect on expression of cognate toxin cbtA i.e. the probable operon is not autoregulatory (PubMed:28257056). Deletion of 3 type IV antitoxin genes (cbeA, yafW, yfjZ) has no effect on cell growth (PubMed:28257056). Encoded in prophage CP4-44. Belongs to the CbeA/YafW/YfjZ antitoxin family.