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==Crystal structure of oxidised Flavodoxin 1 from Bacillus cereus (1.4 A resolution)== | |||
<StructureSection load='6ft1' size='340' side='right' caption='[[6ft1]], [[Resolution|resolution]] 1.40Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[6ft1]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6FT1 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6FT1 FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=FMN:FLAVIN+MONONUCLEOTIDE'>FMN</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</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'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6ft1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6ft1 OCA], [http://pdbe.org/6ft1 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6ft1 RCSB], [http://www.ebi.ac.uk/pdbsum/6ft1 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6ft1 ProSAT]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Flavodoxins are small proteins that shuttle electrons in a range of reactions in microorganisms. Flavodoxins contain a redox-active cofactor, a flavin mononucleotide (FMN), and it is well established that when flavodoxins are reduced by one electron, a peptide bond close to the FMN isoalloxazine ring flips to form a new hydrogen bond with the FMN N5H, stabilising the one-electron reduced state. Here we present high-resolution crystal structures of Flavodoxin 1 from Bacillus cereus in both the oxidised (ox) and one-electron reduced (semiquinone, sq) state. We observe a mixture of conformers in the oxidised state; a 50:50 distribution between the established oxidised conformation where the peptide bond is pointing away from the flavin, and a conformation where the peptide bond is pointing towards the flavin, approximating the conformation in the semiquinone state. We use single-crystal spectroscopy to demonstrate that the mixture of conformers is not caused by radiation damage to the crystal. This is the first time that such a mixture of conformers is reported in a wild-type flavodoxin. We therefore carried out a survey of published flavodoxin structures, which shows that several proteins have a pronounced conformational flexibility of this peptide bond. The degree of flexibility seem to be modulated by the presence, or absence, of stabilising interactions between the peptide bond carbonyl and its surrounding amino acids. We hypothesise that the degree of conformational flexibility will affect the flavodoxin ox/sq redox potential. This article is protected by copyright. All rights reserved. | |||
High-resolution crystal structures reveal a mixture of conformers of the Gly61-Asp62 peptide bond in an oxidised flavodoxin from Bacillus cereus.,Gudim I, Lofstad M, van Beek W, Hersleth HP Protein Sci. 2018 May 3. doi: 10.1002/pro.3436. PMID:29722453<ref>PMID:29722453</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
[[Category: | </div> | ||
[[Category: Hersleth, H | <div class="pdbe-citations 6ft1" style="background-color:#fffaf0;"></div> | ||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Gudim, I]] | |||
[[Category: Hersleth, H P]] | |||
[[Category: Lofstad, M]] | [[Category: Lofstad, M]] | ||
[[Category: | [[Category: Electron transfer]] | ||
[[Category: Electron transport]] | |||
[[Category: Flavodoxin]] | |||
[[Category: Fmn]] | |||
Revision as of 08:47, 11 July 2018
Crystal structure of oxidised Flavodoxin 1 from Bacillus cereus (1.4 A resolution)Crystal structure of oxidised Flavodoxin 1 from Bacillus cereus (1.4 A resolution)
Structural highlights
Publication Abstract from PubMedFlavodoxins are small proteins that shuttle electrons in a range of reactions in microorganisms. Flavodoxins contain a redox-active cofactor, a flavin mononucleotide (FMN), and it is well established that when flavodoxins are reduced by one electron, a peptide bond close to the FMN isoalloxazine ring flips to form a new hydrogen bond with the FMN N5H, stabilising the one-electron reduced state. Here we present high-resolution crystal structures of Flavodoxin 1 from Bacillus cereus in both the oxidised (ox) and one-electron reduced (semiquinone, sq) state. We observe a mixture of conformers in the oxidised state; a 50:50 distribution between the established oxidised conformation where the peptide bond is pointing away from the flavin, and a conformation where the peptide bond is pointing towards the flavin, approximating the conformation in the semiquinone state. We use single-crystal spectroscopy to demonstrate that the mixture of conformers is not caused by radiation damage to the crystal. This is the first time that such a mixture of conformers is reported in a wild-type flavodoxin. We therefore carried out a survey of published flavodoxin structures, which shows that several proteins have a pronounced conformational flexibility of this peptide bond. The degree of flexibility seem to be modulated by the presence, or absence, of stabilising interactions between the peptide bond carbonyl and its surrounding amino acids. We hypothesise that the degree of conformational flexibility will affect the flavodoxin ox/sq redox potential. This article is protected by copyright. All rights reserved. High-resolution crystal structures reveal a mixture of conformers of the Gly61-Asp62 peptide bond in an oxidised flavodoxin from Bacillus cereus.,Gudim I, Lofstad M, van Beek W, Hersleth HP Protein Sci. 2018 May 3. doi: 10.1002/pro.3436. PMID:29722453[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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