2jqj | pdb_00002jqj
NMR structure of yeast Dun1 FHA domain
Structural highlights
Function[DUN1_YEAST] Transducer of the DNA damage signal. Phosphorylates SML1 on serine residues. Cooperates with the PAN deadenylation complex in the regulation of RAD5 mRNA levels and cell survival in response to replicational stress.[1] [2] 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 PubMedForkhead-associated (FHA) domains recognize phosphothreonines, and SQ/TQ cluster domains (SCDs) contain concentrated phosphorylation sites for ATM/ATR-like DNA-damage-response kinases. The Rad53-SCD1 has dual functions in regulating the activation of the Rad53-Dun1 checkpoint kinase cascade but with unknown molecular mechanisms. Here we present structural, biochemical, and genetic evidence that Dun1-FHA possesses an unprecedented diphosphothreonine-binding specificity. The Dun1-FHA has >100-fold increased affinity for diphosphorylated relative to monophosphorylated Rad53-SCD1 due to the presence of two separate phosphothreonine-binding pockets. In vivo, any single threonine of Rad53-SCD1 is sufficient for Rad53 activation and RAD53-dependent survival of DNA damage, but two adjacent phosphothreonines in the Rad53-SCD1 and two phosphothreonine-binding sites in the Dun1-FHA are necessary for Dun1 activation and DUN1-dependent transcriptional responses to DNA damage. The results uncover a phospho-counting mechanism that regulates the specificity of SCD, and provide mechanistic insight into a role of multisite phosphorylation in DNA-damage signaling. Diphosphothreonine-specific interaction between an SQ/TQ cluster and an FHA domain in the Rad53-Dun1 kinase cascade.,Lee H, Yuan C, Hammet A, Mahajan A, Chen ES, Wu MR, Su MI, Heierhorst J, Tsai MD Mol Cell. 2008 Jun 20;30(6):767-78. PMID:18570878[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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