CbtA is a family of bacterial and archaeal toxins of type IV toxin-antitoxin system. Toxins from such systems in free-living bacteria inhibit cell growth by targeting essential functions of cellular metabolism [1]. In this case the toxin inhibits cell-division leading to changes in morphology and finally lysis, by interacting with two essential cytoskeletal proteins, FtsZ and MreB. For FtsZ it inhibits its GTPase activity and GTP-dependent polymerisation, and for MreB it inhibits its ATP-dependent polymerisation. These actions of CbtA appear to occur simultaneously [2]. he cognate antitoxin family is represented by Pfam:PF06154.

1: A novel family of Escherichia coli toxin-antitoxin gene pairs. Brown JM, Shaw KJ; J Bacteriol. 2003;185:6600-6608. PMID:14594833

2: YeeV is an Escherichia coli toxin that inhibits cell division by targeting the cytoskeleton proteins, FtsZ and MreB. Tan Q, Awano N, Inouye M; Mol Microbiol. 2011;79:109-118. PMID:21166897