View source for 1exn


==T5 5'-EXONUCLEASE==
<StructureSection load='1exn' size='340' side='right'caption='[[1exn]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1exn]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_virus_T5 Escherichia virus T5]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EXN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1EXN 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]] 2.5&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</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=1exn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1exn OCA], [https://pdbe.org/1exn PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1exn RCSB], [https://www.ebi.ac.uk/pdbsum/1exn PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1exn ProSAT]</span></td></tr>
</table>
== 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/ex/1exn_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1exn ConSurf].
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== Publication Abstract from PubMed ==
THE 5'-exonucleases are enzymes that are essential for DNA replication and repair. As well as their exonucleolytic action, removing nucleotides from the 5'-end of nucleic acid molecules such as Okazaki fragments, many 5'-3'-exonucleases have been shown to possess endonucleolytic activities. T5 5'-3'-exonuclease shares many similarities with the amino terminal of eubacterial DNA polymerases, although, unlike eubacteria, phages such as T5, T4 and T7 express polymerase and 5'-exonuclease proteins from separate genes. Here we report the 2.5-A crystal structure of the phage T5 5'-exonuclease, which reveals a helical arch for binding DNA. We propose a model consistent with a threading mechanism in which single-stranded DNA could slide through the arch, which is formed by two helices, one containing positively charged, and the other hydrophobic, residues. The active site is at the base of the arch, and contains two metal-binding sites.

A helical arch allowing single-stranded DNA to thread through T5 5'-exonuclease.,Ceska TA, Sayers JR, Stier G, Suck D Nature. 1996 Jul 4;382(6586):90-3. PMID:8657312<ref>PMID:8657312</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 1exn" style="background-color:#fffaf0;"></div>

==See Also==
*[[Exonuclease 3D structures|Exonuclease 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Escherichia virus T5]]
[[Category: Large Structures]]
[[Category: Ceska TA]]
[[Category: Sayers JR]]
[[Category: Stier G]]
[[Category: Suck D]]