2e9n | pdb_00002e9n

Structure of h-CHK1 complexed with A767085

spinqualitylabelsall models 2e9n, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2e9n is a 1 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: 76A Related: 2ayp, 2fga, 2ghg, 2e9o, 2e9p, 2e9u, 2e9v Activity: Non-specific serine/threonine protein kinase, with EC number 2.7.11.1 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum Function [CHK1_HUMAN] Serine/threonine-protein kinase which is required for checkpoint-mediated cell cycle arrest and activation of DNA repair in response to the presence of DNA damage or unreplicated DNA. May also negatively regulate cell cycle progression during unperturbed cell cycles. This regulation is achieved by a number of mechanisms that together help to preserve the integrity of the genome. Recognizes the substrate consensus sequence [R-X-X-S/T]. Binds to and phosphorylates CDC25A, CDC25B and CDC25C. Phosphorylation of CDC25A at 'Ser-178' and 'Thr-507' and phosphorylation of CDC25C at 'Ser-216' creates binding sites for 14-3-3 proteins which inhibit CDC25A and CDC25C. Phosphorylation of CDC25A at 'Ser-76', 'Ser-124', 'Ser-178', 'Ser-279' and 'Ser-293' promotes proteolysis of CDC25A. Phosphorylation of CDC25A at 'Ser-76' primes the protein for subsequent phosphorylation at 'Ser-79', 'Ser-82' and 'Ser-88' by NEK11, which is required for polyubiquitination and degradation of CDCD25A. Inhibition of CDC25 leads to increased inhibitory tyrosine phosphorylation of CDK-cyclin complexes and blocks cell cycle progression. Also phosphorylates NEK6. Binds to and phosphorylates RAD51 at 'Thr-309', which promotes the release of RAD51 from BRCA2 and enhances the association of RAD51 with chromatin, thereby promoting DNA repair by homologous recombination. Phosphorylates multiple sites within the C-terminus of TP53, which promotes activation of TP53 by acetylation and promotes cell cycle arrest and suppression of cellular proliferation. Also promotes repair of DNA cross-links through phosphorylation of FANCE. Binds to and phosphorylates TLK1 at 'Ser-743', which prevents the TLK1-dependent phosphorylation of the chromatin assembly factor ASF1A. This may enhance chromatin assembly both in the presence or absence of DNA damage. May also play a role in replication fork maintenance through regulation of PCNA. May regulate the transcription of genes that regulate cell-cycle progression through the phosphorylation of histones. Phosphorylates histone H3.1 (to form H3T11ph), which leads to epigenetic inhibition of a subset of genes. May also phosphorylate RB1 to promote its interaction with the E2F family of transcription factors and subsequent cell cycle arrest. Isoform 2: Endogenous repressor of isoform 1, interacts with, and antagonizes CHK1 to promote the S to G2/M phase transition. 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 PubMed A new class of checkpoint kinase 1 (CHK-1) inhibitors bearing a 1,4-dihydroindeno[1,2-c]pyrazole core was developed after initial hits from high throughput screening. The efficient hit-to-lead process was facilitated by X-ray crystallography and led to potent inhibitors (<10nM) against CHK-1. X-ray co-crystal structures of bound inhibitors demonstrated that two sub-series of this class of compounds, exemplified by 21 and 41, exhibit distinctive hydrogen bonding patterns in the specificity pocket of the active site. Two compounds, 41 and 43, were capable of potentiating doxorubicin and camptothecin, both DNA-damaging agents, in cell proliferation assays (MTS and soft agar assays) and abrogating G2/M checkpoint in a mechanism-based FACS assay. Discovery of 1,4-dihydroindeno[1,2-c]pyrazoles as a novel class of potent and selective checkpoint kinase 1 inhibitors.,Tong Y, Claiborne A, Stewart KD, Park C, Kovar P, Chen Z, Credo RB, Gu WZ, Gwaltney SL 2nd, Judge RA, Zhang H, Rosenberg SH, Sham HL, Sowin TJ, Lin NH Bioorg Med Chem. 2007 Apr 1;15(7):2759-67. Epub 2007 Jan 17. PMID:17287122 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Serine/threonine protein kinase

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