View source for 2z21


==Crystal Structure of a five site mutated Cyanovirin-N==
<StructureSection load='2z21' size='340' side='right'caption='[[2z21]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2z21]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Nostoc_ellipsosporum Nostoc ellipsosporum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2Z21 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2Z21 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]] 1.8&#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=2z21 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2z21 OCA], [https://pdbe.org/2z21 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2z21 RCSB], [https://www.ebi.ac.uk/pdbsum/2z21 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2z21 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CVN_NOSEL CVN_NOSEL] Mannose-binding lectin.<ref>PMID:9210678</ref> <ref>PMID:12678493</ref> 
== 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/z2/2z21_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=2z21 ConSurf].
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== Publication Abstract from PubMed ==
Cyanovirin-N (CV-N) is a 101 amino acid cyanobacterial lectin with potent antiviral activity against HIV, mediated by high-affinity binding to branched N-linked oligomannosides on the viral surface envelope protein gp120. The protein contains two carbohydrate-binding domains, A and B, each of which binds short oligomannosides independently in vitro. The interaction to gp120 could involve either a single domain or both domains simultaneously; it is not clear which mode would elicit the antiviral activity. The model is complicated by the formation of a domain-swapped dimer form, in which part of each domain is exchanged between two monomers, which contains four functional carbohydrate-binding domains. To clarify whether multivalent interactions with gp120 are necessary for the antiviral activity, we engineered a novel mutant, P51G-m4-CVN, in which the binding site on domain A has been knocked out; in addition, a [P51G] mutation prevents the formation of domain-swapped dimers under physiological conditions. Here, we present the crystal structures at 1.8 A of the free and of the dimannose-bound forms of P51G-m4-CVN, revealing a monomeric structure in which only domain B is bound to dimannose. P51G-m4-CVN binds gp120 with an affinity almost 2 orders of magnitude lower than wt CV-N and is completely inactive against HIV. The tight binding to gp120 is recovered in the domain-swapped version of P51G-m4-CVN, prepared under extreme conditions. Our findings show that the presence of at least two oligomannoside-binding sites, either by the presence of intact domains A and B or by formation of domain-swapped dimers, is essential for activity.

A monovalent mutant of cyanovirin-N provides insight into the role of multiple interactions with gp120 for antiviral activity.,Fromme R, Katiliene Z, Giomarelli B, Bogani F, Mc Mahon J, Mori T, Fromme P, Ghirlanda G Biochemistry. 2007 Aug 14;46(32):9199-207. Epub 2007 Jul 18. PMID:17636873<ref>PMID:17636873</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 2z21" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Nostoc ellipsosporum]]
[[Category: Fromme P]]
[[Category: Fromme R]]
[[Category: Ghirlanda G]]
[[Category: Katilene Z]]