View source for 1ica


==REFINED THREE-DIMENSIONAL STRUCTURE OF INSECT DEFENSIN A==
<StructureSection load='1ica' size='340' side='right'caption='[[1ica]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ica]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Protophormia_terraenovae Protophormia terraenovae]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ICA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1ICA FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR, 10 models</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=1ica FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ica OCA], [https://pdbe.org/1ica PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ica RCSB], [https://www.ebi.ac.uk/pdbsum/1ica PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ica ProSAT]</span></td></tr>
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== Function ==
[https://www.uniprot.org/uniprot/DEFI_PROTE DEFI_PROTE] Responsible for the anti Gram-positive activity of immune hemolymph of P.terraenovae.
== 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/ic/1ica_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=1ica ConSurf].
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== Publication Abstract from PubMed ==
BACKGROUND: Insect defensin A is a basic 4 kDa protein secreted by Phormia terranovae larvae in response to bacterial challenges or injuries. Previous biological tests suggest that the bacterial cytoplasmic membrane is the target of defensin A. The structural study of this protein is the first step towards establishing a structure-activity relationship and forms the basis for understanding its antibiotic activity at the molecular level. RESULTS: We describe a refined model of the three-dimensional structure of defensin A derived from an extensive analysis of 786 inter-proton nuclear Overhauser effects. The backbone fold involves an N-terminal loop and an alpha-helical fragment followed by an antiparallel beta-structure. The helix and the beta-structure are connected by two of the three disulphide bridges present in defensin A, forming a so-called 'cysteine-stabilized alpha beta' (CS alpha beta) motif. The N-terminal loop, which is locally well defined, can occupy different positions with respect to the other moieties of the molecule. CONCLUSIONS: The CS alpha beta motif, which forms the core of the defensin A structure, appears to be a common organization for several families of small proteins with toxic properties. The distribution of amino acid side chains in the protein structure creates several hydrophobic or hydrophilic patches. This leads us to propose that the initial step in the action of positively charged defensin A molecules with cytoplasmic membranes may involve interactions with acidic phospholipids.

Refined three-dimensional solution structure of insect defensin A.,Cornet B, Bonmatin JM, Hetru C, Hoffmann JA, Ptak M, Vovelle F Structure. 1995 May 15;3(5):435-48. PMID:7663941<ref>PMID:7663941</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Defensin 3D structures|Defensin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Protophormia terraenovae]]
[[Category: Bonmatin JM]]
[[Category: Cornet B]]
[[Category: Ptak M]]
[[Category: Vovelle F]]