2wiu | pdb_00002wiu
Mercury-modified bacterial persistence regulator hipBA
Structural highlights
Function[HIPA_ECOLI] Toxic component of a toxin-antitoxin (TA) module. Autophosphorylates (Ser-150) and phosphorylates EF-Tu in vitro (on 'Thr-383'), may act on other proteins as well. The hipA7 mutation leads to increased generation of persister cells, cells that survive antibiotic treatment probably by entering into a dormant state. Wild-type cells produce persisters at a frequency of 10-6 to 10-5 whereas mutant hipA7 cells produce persisters at a frequency of 10-2. Generation of persister cells requires (p)ppGpp as cells lacking relA or relA/spoT generate fewer or no persister cells respectively compared to hipA7. Low level expression of HipA causes cell filamentation and depending on the protein level is toxic enough to reduce cell growth or even kill cells. Expression of wild-type HipA also leads to high antibiotic tolerance of the survivor cells. The toxic effect of HipA is neutralized by its cognate antitoxin HipB. With HipB acts as a corepressor for transcription of the hipBA promoter.[1] [2] [3] [4] [5] [HIPB_ECOLI] Antitoxin component of a toxin-antitoxin (TA) module. Neutralizes the toxic effect of cognate toxin HipA. Binds to operator sites with the consensus sequence 5-'TATCCN(8)GGATA-3' to repress the hipBA operon promoter. 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 PubMedBacterial persistence is the ability of individual cells to randomly enter a period of dormancy during which the cells are protected against antibiotics. In Escherichia coli, persistence is regulated by the activity of a protein kinase HipA and its DNA-binding partner HipB, which is a strong inhibitor of both HipA activity and hip operon transcription. The crystal structure of the HipBA complex was solved by application of the SAD technique to a mercury derivative. In this article, the fortuitous and interesting effect of mercury soaks on the native HipBA crystals is discussed as well as the intriguing tryptophan-binding pocket found on the HipA surface. A HipA-regulation model is also proposed that is consistent with the available structural and biochemical data. New kinase regulation mechanism found in HipBA: a bacterial persistence switch.,Evdokimov A, Voznesensky I, Fennell K, Anderson M, Smith JF, Fisher DA Acta Crystallogr D Biol Crystallogr. 2009 Aug;65(Pt 8):875-9. Epub 2009, Jul 17. PMID:19622872[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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