View source for 1pxi


==HUMAN CYCLIN DEPENDENT KINASE 2 COMPLEXED WITH THE INHIBITOR 4-(2,5-Dichloro-thiophen-3-yl)-pyrimidin-2-ylamine==
<StructureSection load='1pxi' size='340' side='right'caption='[[1pxi]], [[Resolution|resolution]] 1.95&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1pxi]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PXI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1PXI FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.95&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CK1:4-(2,5-DICHLOROTHIEN-3-YL)PYRIMIDIN-2-AMINE'>CK1</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1pxi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1pxi OCA], [https://pdbe.org/1pxi PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1pxi RCSB], [https://www.ebi.ac.uk/pdbsum/1pxi PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1pxi ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CDK2_HUMAN CDK2_HUMAN] Serine/threonine-protein kinase involved in the control of the cell cycle; essential for meiosis, but dispensable for mitosis. Phosphorylates CTNNB1, USP37, p53/TP53, NPM1, CDK7, RB1, BRCA2, MYC, NPAT, EZH2. Interacts with cyclins A, B1, B3, D, or E. Triggers duplication of centrosomes and DNA. Acts at the G1-S transition to promote the E2F transcriptional program and the initiation of DNA synthesis, and modulates G2 progression; controls the timing of entry into mitosis/meiosis by controlling the subsequent activation of cyclin B/CDK1 by phosphorylation, and coordinates the activation of cyclin B/CDK1 at the centrosome and in the nucleus. Crucial role in orchestrating a fine balance between cellular proliferation, cell death, and DNA repair in human embryonic stem cells (hESCs). Activity of CDK2 is maximal during S phase and G2; activated by interaction with cyclin E during the early stages of DNA synthesis to permit G1-S transition, and subsequently activated by cyclin A2 (cyclin A1 in germ cells) during the late stages of DNA replication to drive the transition from S phase to mitosis, the G2 phase. EZH2 phosphorylation promotes H3K27me3 maintenance and epigenetic gene silencing. Phosphorylates CABLES1 (By similarity). Cyclin E/CDK2 prevents oxidative stress-mediated Ras-induced senescence by phosphorylating MYC. Involved in G1-S phase DNA damage checkpoint that prevents cells with damaged DNA from initiating mitosis; regulates homologous recombination-dependent repair by phosphorylating BRCA2, this phosphorylation is low in S phase when recombination is active, but increases as cells progress towards mitosis. In response to DNA damage, double-strand break repair by homologous recombination a reduction of CDK2-mediated BRCA2 phosphorylation. Phosphorylation of RB1 disturbs its interaction with E2F1. NPM1 phosphorylation by cyclin E/CDK2 promotes its dissociates from unduplicated centrosomes, thus initiating centrosome duplication. Cyclin E/CDK2-mediated phosphorylation of NPAT at G1-S transition and until prophase stimulates the NPAT-mediated activation of histone gene transcription during S phase. Required for vitamin D-mediated growth inhibition by being itself inactivated. Involved in the nitric oxide- (NO) mediated signaling in a nitrosylation/activation-dependent manner. USP37 is activated by phosphorylation and thus triggers G1-S transition. CTNNB1 phosphorylation regulates insulin internalization.<ref>PMID:10499802</ref> <ref>PMID:11051553</ref> <ref>PMID:10995386</ref> <ref>PMID:10995387</ref> <ref>PMID:10884347</ref> <ref>PMID:11113184</ref> <ref>PMID:15800615</ref> <ref>PMID:18372919</ref> <ref>PMID:20147522</ref> <ref>PMID:20079829</ref> <ref>PMID:20935635</ref> <ref>PMID:20195506</ref> <ref>PMID:19966300</ref> <ref>PMID:21262353</ref> <ref>PMID:21596315</ref> <ref>PMID:21319273</ref> <ref>PMID:17495531</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/px/1pxi_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1pxi ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
A family of 4-heteroaryl-2-amino-pyrimidine CDK2 inhibitor lead compounds was discovered with the new database-mining program LIDAEUS through in silico screening. Four compounds with IC(50) values ranging from 17 to 0.9 microM were selected for X-ray crystal analysis. Two distinct binding modes are observed, one of which resembles the hydrogen bonding pattern of bound ATP. In the second binding mode, the ligands trigger a conformational change in the activation T loop by inducing movement of Lys(33) and Asp(145) side chains. The family of molecules discovered provides an excellent starting point for the design and synthesis of tight binding inhibitors, which may lead to a new class of antiproliferative drugs.

Discovery of a novel family of CDK inhibitors with the program LIDAEUS: structural basis for ligand-induced disordering of the activation loop.,Wu SY, McNae I, Kontopidis G, McClue SJ, McInnes C, Stewart KJ, Wang S, Zheleva DI, Marriage H, Lane DP, Taylor P, Fischer PM, Walkinshaw MD Structure. 2003 Apr;11(4):399-410. PMID:12679018<ref>PMID:12679018</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1pxi" style="background-color:#fffaf0;"></div>

==See Also==
*[[Cyclin-dependent kinase 3D structures|Cyclin-dependent kinase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Fischer PM]]
[[Category: Kontopidis G]]
[[Category: Lane DP]]
[[Category: Marriage H]]
[[Category: McClue SJ]]
[[Category: McInnes C]]
[[Category: McNae I]]
[[Category: Stewart KJ]]
[[Category: Taylor P]]
[[Category: Walkinshaw MD]]
[[Category: Wang S]]
[[Category: Wu SY]]
[[Category: Zheleva DI]]