View source for 3bco


==Crystal Structure of The Swapped FOrm of P19A/L28Q/N67D BS-RNase==
<StructureSection load='3bco' size='340' side='right'caption='[[3bco]], [[Resolution|resolution]] 2.25&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3bco]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3BCO OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3BCO 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]] 2.25&#8491;</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=3bco FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3bco OCA], [https://pdbe.org/3bco PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3bco RCSB], [https://www.ebi.ac.uk/pdbsum/3bco PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3bco ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RNS_BOVIN RNS_BOVIN] This enzyme hydrolyzes both single- and double-stranded RNA.
== 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/bc/3bco_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=3bco ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
Bovine seminal ribonuclease exists in the native state as an equilibrium mixture of a swapped and an unswapped dimer. The molecular envelope and the exposed surface of the two isomers are practically indistinguishable and their diversity is almost completely buried in the interior of the protein. Surprisingly, the cytotoxic and antitumor activity of the enzyme is a peculiar property of the swapped dimer. This buried diversity comes into light in the reducing environment of the cytosol, where the unswapped dimer dissociates into monomers, whereas the swapped one generates a metastable dimeric form (NCD-BS) with a quaternary assembly that allows the molecule to escape the protein inhibitor of ribonucleases. The stability of this quaternary shape was mainly attributed to the combined presence of Pro19 and Leu28. We have prepared and fully characterized by X-ray diffraction the double mutant P19A/L28Q (PALQ) of the seminal enzyme. While the swapped and unswapped forms of the mutant have structures very similar to that of the corresponding wild-type forms, the non-covalent form (NCD-PALQ) adopts an opened quaternary structure, different from that of NCD-BS. Moreover, model building clearly indicates that NCD-PALQ can be easily sequestered by the protein inhibitor. In agreement with these results, cytotoxic assays have revealed that PALQ has limited activity, whereas the single mutants P19A and L28Q display cytotoxic activity against malignant cells almost as large as the wild-type enzyme. The significant increase in the antitumor activity, brought about by the substitution of just two residues in going from the double mutant to the wild-type enzyme, suggests a new strategy to improve this important biological property by strengthening the interface that stabilizes the quaternary structure of NCD-BS.

The buried diversity of bovine seminal ribonuclease: shape and cytotoxicity of the swapped non-covalent form of the enzyme.,Merlino A, Ercole C, Picone D, Pizzo E, Mazzarella L, Sica F J Mol Biol. 2008 Feb 15;376(2):427-37. Epub 2007 Nov 12. PMID:18164315<ref>PMID:18164315</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 3bco" style="background-color:#fffaf0;"></div>

==See Also==
*[[Ribonuclease 3D structures|Ribonuclease 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bos taurus]]
[[Category: Large Structures]]
[[Category: Ercole C]]
[[Category: Mazzarella L]]
[[Category: Merlino A]]
[[Category: Picone D]]
[[Category: Pizzo E]]
[[Category: Sica F]]