Zeta toxin protein domain
In molecular biology, the protein domain Zeta (ζ) toxin refers to a protein domain found in prokaryotes, which acts as a UDP-N-acetylglucosamine kinase.[1] Its function is to inhibit cell wall biosynthesis and it may act as a bactericide in nature. It is also thought that Zeta toxin induces reversible protective dormancy and permeation to propidium iodide (PI).[2] MechanismThis protein family entry consists of several bacterial zeta toxin proteins. Zeta toxin is thought to be part of a postsegregational killing (PSK) system involved in the killing of plasmid-free cells. It relies on antitoxin/toxin systems that secure stable inheritance of low and medium copy number plasmids during cell division and kill cells that have lost the plasmid.[3] StructureThe Zeta Toxin is folded like a phosphotransferase. This domain features an α/β structure and the central twisted β-sheet contains six β-strands. The first 5 strands are parallel but β-strand 6 is antiparallel and connected by a short loop to β-strand 5. α-Helices are inserted between and flank the β-strands.[3] References
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