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2i53

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[[Image:2i53.jpg|left|200px]]<br /><applet load="2i53" size="350" color="white" frame="true" align="right" spinBox="true"
 
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caption="2i53, resolution 1.50&Aring;" />
 
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'''Crystal structure of Cyclin K'''<br />
 
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==Overview==
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==Crystal structure of Cyclin K==
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Cyclin K and the closely related cyclins T1, T2a, and T2b interact with cyclin-dependent kinase 9 (CDK9) forming multiple nuclear complexes, referred to collectively as positive transcription elongation factor b (P-TEFb). Through phosphorylation of the C-terminal domain of the RNA polymerase II largest subunit, distinct P-TEFb species regulate the transcriptional elongation of specific genes that play central roles in human physiology and disease development, including cardiac hypertrophy and human immunodeficiency virus-1 pathogenesis. We have determined the crystal structure of human cyclin K (residues 11-267) at 1.5 A resolution, which represents the first atomic structure of a P-TEFb subunit. The cyclin K fold comprises two typical cyclin boxes with two short helices preceding the N-terminal box. A prominent feature of cyclin K is an additional helix (H4a) in the first cyclin box that obstructs the binding pocket for the cell-cycle inhibitor p27(Kip1). Modeling of CDK9 bound to cyclin K provides insights into the structural determinants underlying the formation and regulation of this complex. A homology model of human cyclin T1 generated using the cyclin K structure as a template reveals that the two proteins have similar structures, as expected from their high level of sequence identity. Nevertheless, their CDK9-interacting surfaces display significant structural differences, which could potentially be exploited for the design of cyclin-targeted inhibitors of the CDK9-cyclin K and CDK9-cyclin T1 complexes.
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<StructureSection load='2i53' size='340' side='right'caption='[[2i53]], [[Resolution|resolution]] 1.50&Aring;' scene=''>
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== Structural highlights ==
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<table><tr><td colspan='2'>[[2i53]] 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=2I53 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2I53 FirstGlance]. <br>
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</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.5&#8491;</td></tr>
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<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene></td></tr>
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<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2i53 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2i53 OCA], [https://pdbe.org/2i53 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2i53 RCSB], [https://www.ebi.ac.uk/pdbsum/2i53 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2i53 ProSAT]</span></td></tr>
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</table>
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== Function ==
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[https://www.uniprot.org/uniprot/CCNK_HUMAN CCNK_HUMAN] May play a role in transcriptional regulation. In vitro, is associated with a kinase activity toward both RNA polymerase II C-terminal domain and CDK2 (CAK).<ref>PMID:10574912</ref>
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== Evolutionary Conservation ==
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[[Image:Consurf_key_small.gif|200px|right]]
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Check<jmol>
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<jmolCheckbox>
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<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/i5/2i53_consurf.spt"</scriptWhenChecked>
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<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
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<text>to colour the structure by Evolutionary Conservation</text>
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</jmolCheckbox>
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</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=2i53 ConSurf].
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<div style="clear:both"></div>
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==About this Structure==
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==See Also==
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2I53 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=ACT:'>ACT</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2I53 OCA].
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*[[Cyclin 3D structures|Cyclin 3D structures]]
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== References ==
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==Reference==
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<references/>
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Crystal structure of human cyclin K, a positive regulator of cyclin-dependent kinase 9., Baek K, Brown RS, Birrane G, Ladias JA, J Mol Biol. 2007 Feb 16;366(2):563-73. Epub 2006 Nov 18. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17169370 17169370]
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__TOC__
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Homo sapiens]]
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[[Category: Single protein]]
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[[Category: Large Structures]]
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[[Category: Baek, K.]]
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[[Category: Baek K]]
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[[Category: Birrane, G.]]
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[[Category: Birrane G]]
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[[Category: Brown, R S.]]
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[[Category: Brown RS]]
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[[Category: Ladias, J A.A.]]
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[[Category: Ladias JAA]]
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[[Category: ACT]]
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[[Category: cdk9]]
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[[Category: cell cycle]]
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[[Category: cyclin box]]
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[[Category: cyclin k]]
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[[Category: p-tefb]]
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[[Category: positive transcription elongation factor]]
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[[Category: transcription]]
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:49:11 2008''
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Current revision

Crystal structure of Cyclin K

PDB ID 2i53

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