1mvf
MazE addiction antidote
Structural highlights
FunctionMAZE_ECOLI Antitoxin component of a toxin-antitoxin (TA) module. Labile antitoxin that binds to the MazF mRNA interferase toxin and neutralizes its endoribonuclease activity. Is considered to be an 'addiction' molecule as the cell will die in its absence. The endoribonuclease activity (MazF, a toxin) is inhibited by the labile cognate antitoxin MazE. Toxicity results when the levels of MazE decrease in the cell, leading to mRNA degradation. This effect can be rescued by expression of MazE, but after 6 hours in rich medium the overexpression of MazF leads to programmed cell death. Cell growth and viability are not affected when MazF and MazE are coexpressed. Both MazE and MazE-MazF bind to the promoter region of the mazE-mazF operon to inhibit their transcription. Cell death governed by the MazE-MazF and DinJ-YafQ TA modules seems to play a role in biofilm formation, while MazE-MazF is also implicated in cell death in liquid media. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedA specific camel VHH (variable domain of dromedary heavy chain antibody) fragment was used to crystallize the intrinsically flexible addiction antidote MazE. Only 45% of the polypeptide chain is found ordered in the crystal. The MazE monomer consisting of two beta-hairpins connected by a short alpha-helix has no hydrophobic core on its own and represents only one half of a typical protein domain. A complete domain structure is formed by the association of two chains, creating a hydrophobic core between two four-stranded beta-sheets. This hydrophobic core consists exclusively of short aliphatic residues. The folded part of MazE contains a novel DNA binding motif. A model for DNA binding that is consistent with the available biochemical data is presented. Crystal structure of the intrinsically flexible addiction antidote MazE.,Loris R, Marianovsky I, Lah J, Laeremans T, Engelberg-Kulka H, Glaser G, Muyldermans S, Wyns L J Biol Chem. 2003 Jul 25;278(30):28252-7. Epub 2003 May 12. PMID:12743116[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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