CbeA_antitoxin, type IV, cytoskeleton bundling-enhancing factor A
CbeA_antitoxin is a family of cognate antitoxins to the CbtA toxins that act by inhibiting the polymerization of cytoskeletal proteins, see pfam06755. These are classified as a type IV toxin-antitoxin system. The family includes three proteins from E. coli YagB, YeeU and YfjZ, which act not by forming a complex with CbtA but through acting as antagonists to the CbtA toxicity, by stabilizing the CbtA target proteins. For example, YeeU binds directly to both MreB and FtsZ and enhances the bundling of their filaments in vitro. YeeU is also able to neutralize the toxicity caused by other MreB and FtsZ inhibitors, such as A22 [S-(3, 4-dichlorobenzyl)isothiourea] for MreB, and SulA and DicB for FtsZ. Thus CbeA, for cytoskeleton bundling-enhancing factor A, is proposed as a general name for all of these antitoxin proteins.