View source for 1h26


==CDK2/CyclinA in complex with an 11-residue recruitment peptide from p53==
<StructureSection load='1h26' size='340' side='right'caption='[[1h26]], [[Resolution|resolution]] 2.24&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1h26]] is a 5 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=1H26 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1H26 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]] 2.24&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=TPO:PHOSPHOTHREONINE'>TPO</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=1h26 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1h26 OCA], [https://pdbe.org/1h26 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1h26 RCSB], [https://www.ebi.ac.uk/pdbsum/1h26 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1h26 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CCNA2_HUMAN CCNA2_HUMAN] Essential for the control of the cell cycle at the G1/S (start) and the G2/M (mitosis) transitions.
== 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/h2/1h26_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=1h26 ConSurf].
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== Publication Abstract from PubMed ==
Progression through S phase of the eukaryotic cell cycle is regulated by the action of the cyclin dependent protein kinase 2 (CDK2) in association with cyclin A. CDK2/cyclin A phosphorylates numerous substrates. Substrate specificity often employs a dual recognition strategy in which the sequence flanking the phospho-acceptor site (Ser.Pro.X.Arg/Lys) is recognized by CDK2, while the cyclin A component of the complex contains a hydrophobic site that binds Arg/Lys.X.Leu ("RXL" or "KXL") substrate recruitment motifs. To determine additional sequence specificity motifs around the RXL sequence, we have performed X-ray crystallographic studies at 2.3 A resolution and isothermal calorimetry measurements on complexes of phospho-CDK2/cyclin A with a recruitment peptide derived from E2F1 and with shorter 11-mer peptides from p53, pRb, p27, E2F1, and p107. The results show that the cyclin recruitment site accommodates a second hydrophobic residue either immediately C-terminal or next adjacent to the leucine of the "RXL" motif and that this site makes important contributions to the recruitment peptide recognition. The arginine of the RXL motif contacts a glutamate, Glu220, on the cyclin. In those substrates that contain a KXL motif, no ionic interactions are observed with the lysine. The sequences N-terminal to the "RXL" motif of the individual peptides show no conservation, but nevertheless make common contacts to the cyclin through main chain interactions. Thus, the recruitment site is able to recognize diverse but conformationally constrained target sequences. The observations have implications for the further identification of physiological substrates of CDK2/cyclin A and the design of specific inhibitors.

Specificity determinants of recruitment peptides bound to phospho-CDK2/cyclin A.,Lowe ED, Tews I, Cheng KY, Brown NR, Gul S, Noble ME, Gamblin SJ, Johnson LN Biochemistry. 2002 Dec 31;41(52):15625-34. PMID:12501191<ref>PMID:12501191</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 1h26" style="background-color:#fffaf0;"></div>

==See Also==
*[[Cyclin 3D structures|Cyclin 3D structures]]
*[[Cyclin-dependent kinase 3D structures|Cyclin-dependent kinase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Brown NR]]
[[Category: Cheng KY]]
[[Category: Gamblin S]]
[[Category: Gul S]]
[[Category: Johnson LN]]
[[Category: Lowe ED]]
[[Category: Noble MEM]]
[[Category: Tews I]]