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Crystal structure of the MDC1 brct repeat in complex with the histone tail of gamma-H2AXCrystal structure of the MDC1 brct repeat in complex with the histone tail of gamma-H2AX
Structural highlights
FunctionMDC1_HUMAN Required for checkpoint mediated cell cycle arrest in response to DNA damage within both the S phase and G2/M phases of the cell cycle. May serve as a scaffold for the recruitment of DNA repair and signal transduction proteins to discrete foci of DNA damage marked by 'Ser-139' phosphorylation of histone H2AFX. Also required for downstream events subsequent to the recruitment of these proteins. These include phosphorylation and activation of the ATM, CHEK1 and CHEK2 kinases, and stabilization of TP53 and apoptosis. ATM and CHEK2 may also be activated independently by a parallel pathway mediated by TP53BP1.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] 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 PubMedHistone variant H2AX phosphorylation in response to DNA damage is the major signal for recruitment of DNA-damage-response proteins to regions of damaged chromatin. Loss of H2AX causes radiosensitivity, genome instability, and DNA double-strand-break repair defects, yet the mechanisms underlying these phenotypes remain obscure. Here, we demonstrate that mammalian MDC1/NFBD1 directly binds to phospho-H2AX (gammaH2AX) by specifically interacting with the phosphoepitope at the gammaH2AX carboxyl terminus. Moreover, through a combination of biochemical, cell-biological, and X-ray crystallographic approaches, we reveal the molecular details of the MDC1/NFBD1-gammaH2AX complex. These data provide compelling evidence that the MDC1/NFBD1 BRCT repeat domain is the major mediator of gammaH2AX recognition following DNA damage. We further show that MDC1/NFBD1-gammaH2AX complex formation regulates H2AX phosphorylation and is required for normal radioresistance and efficient accumulation of DNA-damage-response proteins on damaged chromatin. Thus, binding of MDC1/NFBD1 to gammaH2AX plays a central role in the mammalian response to DNA damage. MDC1 directly binds phosphorylated histone H2AX to regulate cellular responses to DNA double-strand breaks.,Stucki M, Clapperton JA, Mohammad D, Yaffe MB, Smerdon SJ, Jackson SP Cell. 2005 Dec 29;123(7):1213-26. PMID:16377563[11] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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