3kx9: Difference between revisions
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< | ==Engineering a closed form of the Archaeoglobus fulgidus ferritin by site directed mutagenesis== | ||
<StructureSection load='3kx9' size='340' side='right'caption='[[3kx9]], [[Resolution|resolution]] 2.10Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3kx9]] is a 24 chain structure with sequence from [https://en.wikipedia.org/wiki/Archaeoglobus_fulgidus Archaeoglobus fulgidus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3KX9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3KX9 FirstGlance]. <br> | |||
or | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.101Å</td></tr> | ||
- | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</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=3kx9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3kx9 OCA], [https://pdbe.org/3kx9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3kx9 RCSB], [https://www.ebi.ac.uk/pdbsum/3kx9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3kx9 ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/O29424_ARCFU O29424_ARCFU] | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Archaeoglobus fulgidus ferritin (AfFtn) is the only tetracosameric ferritin known to form a tetrahedral cage, a structure that remains unique in structural biology. As a result of the tetrahedral (2-3) symmetry, four openings ( approximately 45 A in diameter) are formed in the cage. This open tetrahedral assembly contradicts the paradigm of a typical ferritin cage: a closed assembly having octahedral (4-3-2) symmetry. To investigate the molecular mechanism affecting this atypical assembly, amino acid residues Lys-150 and Arg-151 were replaced by alanine. The data presented here shed light on the role that these residues play in shaping the unique structural features and biophysical properties of the AfFtn. The x-ray crystal structure of the K150A/R151A mutant, solved at 2.1 A resolution, indicates that replacement of these key residues flips a "symmetry switch." The engineered molecule no longer assembles with tetrahedral symmetry but forms a typical closed octahedral ferritin cage. Small angle x-ray scattering reveals that the overall shape and size of AfFtn and AfFtn-AA in solution are consistent with those observed in their respective crystal structures. Iron binding and release kinetics of the AfFtn and AfFtn-AA were investigated to assess the contribution of cage openings to the kinetics of iron oxidation, mineralization, or reductive iron release. Identical iron binding kinetics for AfFtn and AfFtn-AA suggest that Fe(2+) ions do not utilize the triangular pores for access to the catalytic site. In contrast, relatively slow reductive iron release was observed for the closed AfFtn-AA, demonstrating involvement of the large pores in the pathway for iron release. | |||
The role of nonconserved residues of Archaeoglobus fulgidus ferritin on its unique structure and biophysical properties.,Sana B, Johnson E, Le Magueres P, Criswell A, Cascio D, Lim S J Biol Chem. 2013 Nov 8;288(45):32663-72. doi: 10.1074/jbc.M113.491191. Epub 2013, Sep 12. PMID:24030827<ref>PMID:24030827</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 3kx9" style="background-color:#fffaf0;"></div> | |||
== | ==See Also== | ||
*[[Ferritin 3D structures|Ferritin 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Archaeoglobus fulgidus]] | [[Category: Archaeoglobus fulgidus]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: | [[Category: Cascio D]] | ||
[[Category: | [[Category: Johnson E]] | ||
[[Category: | [[Category: Sawaya MR]] | ||
Latest revision as of 11:26, 6 September 2023
Engineering a closed form of the Archaeoglobus fulgidus ferritin by site directed mutagenesisEngineering a closed form of the Archaeoglobus fulgidus ferritin by site directed mutagenesis
Structural highlights
FunctionPublication Abstract from PubMedArchaeoglobus fulgidus ferritin (AfFtn) is the only tetracosameric ferritin known to form a tetrahedral cage, a structure that remains unique in structural biology. As a result of the tetrahedral (2-3) symmetry, four openings ( approximately 45 A in diameter) are formed in the cage. This open tetrahedral assembly contradicts the paradigm of a typical ferritin cage: a closed assembly having octahedral (4-3-2) symmetry. To investigate the molecular mechanism affecting this atypical assembly, amino acid residues Lys-150 and Arg-151 were replaced by alanine. The data presented here shed light on the role that these residues play in shaping the unique structural features and biophysical properties of the AfFtn. The x-ray crystal structure of the K150A/R151A mutant, solved at 2.1 A resolution, indicates that replacement of these key residues flips a "symmetry switch." The engineered molecule no longer assembles with tetrahedral symmetry but forms a typical closed octahedral ferritin cage. Small angle x-ray scattering reveals that the overall shape and size of AfFtn and AfFtn-AA in solution are consistent with those observed in their respective crystal structures. Iron binding and release kinetics of the AfFtn and AfFtn-AA were investigated to assess the contribution of cage openings to the kinetics of iron oxidation, mineralization, or reductive iron release. Identical iron binding kinetics for AfFtn and AfFtn-AA suggest that Fe(2+) ions do not utilize the triangular pores for access to the catalytic site. In contrast, relatively slow reductive iron release was observed for the closed AfFtn-AA, demonstrating involvement of the large pores in the pathway for iron release. The role of nonconserved residues of Archaeoglobus fulgidus ferritin on its unique structure and biophysical properties.,Sana B, Johnson E, Le Magueres P, Criswell A, Cascio D, Lim S J Biol Chem. 2013 Nov 8;288(45):32663-72. doi: 10.1074/jbc.M113.491191. Epub 2013, Sep 12. PMID:24030827[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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