View source for 1kej


==Crystal Structure of Murine Terminal Deoxynucleotidyl Transferase complexed with ddATP==
<StructureSection load='1kej' size='340' side='right'caption='[[1kej]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1kej]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KEJ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1KEJ 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]] 3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CO:COBALT+(II)+ION'>CO</scene>, <scene name='pdbligand=DAD:2,3-DIDEOXYADENOSINE-5-TRIPHOSPHATE'>DAD</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</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=1kej FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1kej OCA], [https://pdbe.org/1kej PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1kej RCSB], [https://www.ebi.ac.uk/pdbsum/1kej PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1kej ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TDT_MOUSE TDT_MOUSE] Template-independent DNA polymerase which catalyzes the random addition of deoxynucleoside 5'-triphosphate to the 3'-end of a DNA initiator. One of the in vivo functions of this enzyme is the addition of nucleotides at the junction (N region) of rearranged Ig heavy chain and T-cell receptor gene segments during the maturation of B- and T-cells.
== 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/ke/1kej_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=1kej ConSurf].
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== Publication Abstract from PubMed ==
The crystal structure of the catalytic core of murine terminal deoxynucleotidyltransferase (TdT) at 2.35 A resolution reveals a typical DNA polymerase beta-like fold locked in a closed form. In addition, the structures of two different binary complexes, one with an oligonucleotide primer and the other with an incoming ddATP-Co(2+) complex, show that the substrates and the two divalent ions in the catalytic site are positioned in TdT in a manner similar to that described for the human DNA polymerase beta ternary complex, suggesting a common two metal ions mechanism of nucleotidyl transfer in these two proteins. The inability of TdT to accommodate a template strand can be explained by steric hindrance at the catalytic site caused by a long lariat-like loop, which is absent in DNA polymerase beta. However, displacement of this discriminating loop would be sufficient to unmask a number of evolutionarily conserved residues, which could then interact with a template DNA strand. The present structure can be used to model the recently discovered human polymerase mu, with which it shares 43% sequence identity.

Crystal structures of a template-independent DNA polymerase: murine terminal deoxynucleotidyltransferase.,Delarue M, Boule JB, Lescar J, Expert-Bezancon N, Jourdan N, Sukumar N, Rougeon F, Papanicolaou C EMBO J. 2002 Feb 1;21(3):427-39. PMID:11823435<ref>PMID:11823435</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 1kej" style="background-color:#fffaf0;"></div>

==See Also==
*[[DNA polymerase 3D structures|DNA polymerase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Mus musculus]]
[[Category: Boule JB]]
[[Category: Delarue M]]
[[Category: Expert-Bezancon N]]
[[Category: Jourdan N]]
[[Category: Lescar J]]
[[Category: Papanicolaou C]]
[[Category: Rougeon F]]
[[Category: Sukumar N]]