View source for 4qyg

==CHK1 kinase domain in complex with diazacarbazole compound 14==
<StructureSection load='4qyg' size='340' side='right' caption='[[4qyg]], [[Resolution|resolution]] 1.75&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4qyg]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4QYG OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4QYG FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=3DW:3-[4-(4-METHYLPIPERAZIN-1-YL)PHENYL]-9H-PYRROLO[2,3-B 5,4-C]DIPYRIDINE-6-CARBOXYLIC+ACID'>3DW</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4qye|4qye]], [[4qyf|4qyf]], [[4qyh|4qyh]]</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Non-specific_serine/threonine_protein_kinase Non-specific serine/threonine protein kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.11.1 2.7.11.1] </span></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4qyg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4qyg OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4qyg RCSB], [http://www.ebi.ac.uk/pdbsum/4qyg PDBsum]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/CHK1_HUMAN 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.<ref>PMID:9278511</ref> <ref>PMID:10673501</ref> <ref>PMID:11535615</ref> <ref>PMID:12446774</ref> <ref>PMID:12399544</ref> <ref>PMID:12676583</ref> <ref>PMID:12660173</ref> <ref>PMID:14681206</ref> <ref>PMID:12676925</ref> <ref>PMID:12759351</ref> <ref>PMID:14559997</ref> <ref>PMID:14988723</ref> <ref>PMID:15311285</ref> <ref>PMID:15659650</ref> <ref>PMID:15665856</ref> <ref>PMID:15650047</ref> <ref>PMID:16511572</ref> <ref>PMID:16963448</ref> <ref>PMID:17380128</ref> <ref>PMID:17296736</ref> <ref>PMID:18510930</ref> <ref>PMID:18728393</ref> <ref>PMID:18451105</ref> <ref>PMID:18317453</ref> <ref>PMID:19734889</ref> <ref>PMID:20090422</ref>   Isoform 2: Endogenous repressor of isoform 1, interacts with, and antagonizes CHK1 to promote the S to G2/M phase transition.<ref>PMID:9278511</ref> <ref>PMID:10673501</ref> <ref>PMID:11535615</ref> <ref>PMID:12446774</ref> <ref>PMID:12399544</ref> <ref>PMID:12676583</ref> <ref>PMID:12660173</ref> <ref>PMID:14681206</ref> <ref>PMID:12676925</ref> <ref>PMID:12759351</ref> <ref>PMID:14559997</ref> <ref>PMID:14988723</ref> <ref>PMID:15311285</ref> <ref>PMID:15659650</ref> <ref>PMID:15665856</ref> <ref>PMID:15650047</ref> <ref>PMID:16511572</ref> <ref>PMID:16963448</ref> <ref>PMID:17380128</ref> <ref>PMID:17296736</ref> <ref>PMID:18510930</ref> <ref>PMID:18728393</ref> <ref>PMID:18451105</ref> <ref>PMID:18317453</ref> <ref>PMID:19734889</ref> <ref>PMID:20090422</ref>  
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Checkpoint kinase 1 (ChK1) is activated in response to DNA damage, acting to temporarily block cell cycle progression and allow for DNA repair. It is envisaged that inhibition of ChK1 will sensitize tumor cells to treatment with DNA-damaging therapies, and may enhance the therapeutic window. High throughput screening identified carboxylate-containing diarylpyrazines as a prominent hit series, but with limited biochemical potency and no cellular activity. Through a series of SAR investigations and X-ray crystallographic analysis the critical role of polar contacts with conserved waters in the kinase back pocket was established. Structure-based design, guided by in silico modeling, transformed the series to better satisfy these contacts and the novel 1,7-diazacarbazole class of inhibitors was discovered. Here we present the genesis of this novel series and the identification of GNE-783, a potent, selective and orally bioavailable inhibitor of ChK1.

Discovery of the 1,7-diazacarbazole class of inhibitors of checkpoint kinase 1.,Gazzard L, Appleton B, Chapman K, Chen H, Clark K, Drobnick J, Goodacre S, Halladay J, Lyssikatos J, Schmidt S, Sideris S, Wiesmann C, Williams K, Wu P, Yen I, Malek S Bioorg Med Chem Lett. 2014 Dec 15;24(24):5704-9. doi: 10.1016/j.bmcl.2014.10.063., Epub 2014 Oct 27. PMID:25453805<ref>PMID:25453805</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Non-specific serine/threonine protein kinase]]
[[Category: Wiesmann, C]]
[[Category: Wu, P]]
[[Category: Phosphotransfer catalyst]]
[[Category: Protein kinase]]
[[Category: Transferase-transferase inhibitor complex]]