3dtk
Crystal structure of the IRRE protein, a central regulator of DNA damage repair in deinococcaceae
Structural highlights
FunctionIRRE_DEIDV Plays a central regulatory role in DNA repair and protection pathways in response to radiation stress. Acts as a site-specific metalloprotease that cleaves and inactivates the repressor proteins DdrOC and DdrOP3, resulting in induced expression of genes required for DNA repair and cell survival after exposure to radiation.[1] 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 PubMedDeinococcaceae are famous for their extreme radioresistance. Transcriptome analysis in Deinococcus radiodurans revealed a group of genes up-regulated in response to desiccation and ionizing radiation. IrrE, a novel protein initially found in D. radiodurans, was shown to be a positive regulator of some of these genes. Deinococcus deserti irrE is able to restore radioresistance in a D. radiodurans DeltairrE mutant. The D. deserti IrrE crystal structure reveals a unique combination of three domains: one zinc peptidase-like domain, one helix-turn-helix motif and one GAF-like domain. Mutant analysis indicates that the first and third domains are critical regions for radiotolerance. In particular, mutants affected in the putative zinc-binding site are as sensitive to gamma and UV irradiation as the DeltairrE bacteria, and radioresistance is strongly decreased with the H217L mutation present in the C-terminal domain. In addition, modeling of IrrE-DNA interaction suggests that the observed IrrE structure may not bind double-stranded DNA through its central helix-turn-helix motif and that IrrE is not a classic transcriptional factor that activates gene expression by its direct binding to DNA. We propose that the putative protease activity of IrrE could be a key element of transcription enhancement and that a more classic transcription factor, possibly an IrrE substrate, would link IrrE to transcription of genes specifically involved in radioresistance. Crystal Structure of the IrrE Protein, a Central Regulator of DNA Damage Repair in Deinococcaceae.,Vujicic-Zagar A, Dulermo R, Le Gorrec M, Vannier F, Servant P, Sommer S, de Groot A, Serre L J Mol Biol. 2009 Jan 3. PMID:19150362[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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