View source for 1ftc


==Y13C MUTANT OF AZOTOBACTER VINELANDII FDI==
<StructureSection load='1ftc' size='340' side='right'caption='[[1ftc]], [[Resolution|resolution]] 2.35&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ftc]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Azotobacter_vinelandii Azotobacter vinelandii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1FTC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1FTC 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]] 2.35&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CSS:S-MERCAPTOCYSTEINE'>CSS</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=1ftc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ftc OCA], [https://pdbe.org/1ftc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ftc RCSB], [https://www.ebi.ac.uk/pdbsum/1ftc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ftc ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/FER1_AZOVI FER1_AZOVI] Ferredoxins are iron-sulfur proteins that transfer electrons in a wide variety of metabolic reactions. This ferredoxin could play a role in regulating gene expression by interacting directly with DNA.
== 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/ft/1ftc_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=1ftc ConSurf].
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== Publication Abstract from PubMed ==
Ferredoxins that contain [4Fe-4S]2+/+ clusters often obtain three of their four cysteine ligands from a highly conserved CysXXCysXXCys sequence motif. Little is known about the in vivo assembly of these clusters and the role that this sequence motif plays in that process. In this study, we have used structure as a guide in attempts to direct the formation of a [4Fe-4S]2+/+ in the [3Fe-4S]+/0 location of native (7Fe) Azotobacter vinelandii ferredoxin I (AvFdI) by providing the correct three-dimensional orientation of cysteine ligands without introducing a CysXXCysXXCys motif. Tyr13 of AvFdI occupies the position of the fourth ligating cysteine in the homologous and structurally characterized 8Fe ferredoxin from Peptococcus aerogenes and a Y13C variant of AvFdI could be easily modeled as an 8Fe protein. However, characterization of purified Y13C FdI by UV-visible spectra, circular dichroism, electron paramagnetic resonance spectroscopies, and by x-ray crystallography revealed that the protein failed to use the introduced cysteine as a ligand and retained its [3Fe-4S]+/0 cluster. Further, electrochemical characterization showed that the redox potential and pH behavior of the cluster were unaffected by the substitution of Tyr by Cys. Although Y13C FdI is functional in vivo it does differ significantly from native FdI in that it is extremely unstable in the reduced state possibly due to increased solvent exposure of the [3Fe-4S]0 cluster. Surprisingly, the x-ray structure showed that the introduced cysteine was modified to become a persulfide. This modification may have occurred in vivo via the action of NifS, which is known to be expressed under the growth conditions used. It is interesting to note that neither of the two free cysteines present in FdI was modified. Thus, if NifS is involved in modifying the introduced cysteine there must be specificity to the reaction.

Y13C Azotobacter vinelandii ferredoxin I. A designed [Fe-S] ligand motif contains a cysteine persulfide.,Kemper MA, Stout CD, Lloyd SJ, Prasad GS, Fawcett SE, Armstrong FA, Shen B, Burgess BK J Biol Chem. 1997 Jun 20;272(25):15620-7. PMID:9188450<ref>PMID:9188450</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Ferredoxin 3D structures|Ferredoxin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Azotobacter vinelandii]]
[[Category: Large Structures]]
[[Category: Armstrong FA]]
[[Category: Burgess BK]]
[[Category: Fawcett S]]
[[Category: Kemper MA]]
[[Category: Lloyd SJ]]
[[Category: Prasad GS]]
[[Category: Stout CD]]