View source for 3snf


==Onconase, atomic resolution crystal structure==
<StructureSection load='3snf' size='340' side='right'caption='[[3snf]], [[Resolution|resolution]] 1.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3snf]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Lithobates_pipiens Lithobates pipiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3SNF OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3SNF 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]] 1.1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=PCA:PYROGLUTAMIC+ACID'>PCA</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=3snf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3snf OCA], [https://pdbe.org/3snf PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3snf RCSB], [https://www.ebi.ac.uk/pdbsum/3snf PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3snf ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RNP30_LITPI RNP30_LITPI] Basic protein with antiproliferative/cytotoxic activity against several tumor cell lines in vitro, as well as antitumor in vivo. It exhibits a ribonuclease-like activity against high molecular weight ribosomal RNA.
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== Publication Abstract from PubMed ==
Onconase((R)) (ONC) is an amphibian member of the pancreatic ribonuclease superfamily that is selectively toxic to tumor cells. It is a much less efficient enzyme than the archetypal ribonuclease A and, in an attempt to gain further insight, we report the first atomic resolution crystal structure of ONC, determined in complex with sulfate ions at 100 K. The electron density map is of a quality sufficient to reveal significant nonplanarity in several peptide bonds. The majority of active site residues are very well defined, with the exceptions being Lys31 from the catalytic triad and Lys33 from the B(1) subsite, which are relatively mobile but rigidify upon nucleotide binding. Cryocooling causes a compaction of the unit cell and the protein contained within. This is principally the result of an inward movement of one of the lobes of the enzyme (lobe 2), which also narrows the active site cleft. Binding a nucleotide in place of sulfate is associated with an approximately perpendicular movement of lobe 2 and has little further effect on the cleft width. Aspects of this deformation are present in the principal axes of anisotropy extracted from C(alpha) atomic displacement parameters, indicating its intrinsic nature. The three lowest-frequency modes of ONC motion predicted by an anisotropic network model are compaction/expansion variations in which lobe 2 is the prime mover. Two of these have high similarity to the cryocooling response and imply that the essential 'breathing' motion of ribonuclease A is conserved in ONC. Instead, shifts in conformational equilibria may contribute to the reduced ribonucleolytic activity of ONC.

Crystal structure of Onconase at 1.1 A resolution--insights into substrate binding and collective motion.,Holloway DE, Singh UP, Shogen K, Acharya KR FEBS J. 2011 Nov;278(21):4136-49. doi: 10.1111/j.1742-4658.2011.08320.x. Epub, 2011 Sep 28. PMID:21895975<ref>PMID:21895975</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 3snf" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Lithobates pipiens]]
[[Category: Acharya KR]]
[[Category: Holloway DE]]
[[Category: Shogen K]]
[[Category: Singh UP]]