5TRE

Zinc and the Iron Donor Frataxin Regulate Oligomerization of the Scaffold Protein to Form New Fe-S Cluster Assembly Centers


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 15.6 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Zinc and the iron donor frataxin regulate oligomerization of the scaffold protein to form new Fe-S cluster assembly centers.

Galeano, B.K.Ranatunga, W.Gakh, O.Smith, D.Y.Thompson, J.R.Isaya, G.

(2017) Metallomics 9: 773-801

  • DOI: 10.1039/c7mt00089h
  • Primary Citation of Related Structures:  
    5TRE

  • PubMed Abstract: 
  • Early studies of the bacterial Fe-S cluster assembly system provided structural details for how the scaffold protein and the cysteine desulfurase interact. This work and additional work on the yeast and human systems elucidated a conserved mechanism for sulfur donation but did not provide any conclusive insights into the mechanism for iron delivery from the iron donor, frataxin, to the scaffold ...

    Early studies of the bacterial Fe-S cluster assembly system provided structural details for how the scaffold protein and the cysteine desulfurase interact. This work and additional work on the yeast and human systems elucidated a conserved mechanism for sulfur donation but did not provide any conclusive insights into the mechanism for iron delivery from the iron donor, frataxin, to the scaffold. We previously showed that oligomerization is a mechanism by which yeast frataxin (Yfh1) can promote assembly of the core machinery for Fe-S cluster synthesis both in vitro and in cells, in such a manner that the scaffold protein, Isu1, can bind to Yfh1 independent of the presence of the cysteine desulfurase, Nfs1. Here, in the absence of Yfh1, Isu1 was found to exist in two forms, one mostly monomeric with limited tendency to dimerize, and one with a strong propensity to oligomerize. Whereas the monomeric form is stabilized by zinc, the loss of zinc promotes formation of dimer and higher order oligomers. However, upon binding to oligomeric Yfh1, both forms take on a similar symmetrical trimeric configuration that places the Fe-S cluster coordinating residues of Isu1 in close proximity of iron-binding residues of Yfh1. This configuration is suitable for docking of Nfs1 in a manner that provides a structural context for coordinate iron and sulfur donation to the scaffold. Moreover, distinct structural features suggest that in physiological conditions the zinc-regulated abundance of monomeric vs. oligomeric Isu1 yields [Yfh1]·[Isu1] complexes with different Isu1 configurations that afford unique functional properties for Fe-S cluster assembly and delivery.


    Organizational Affiliation

    Department of Pediatric & Adolescent Medicine, Mayo Clinic, Rochester, Minnesota, USA. gakh.oleksandr@mayo.edu isaya@mayo.edu.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Iron sulfur cluster assembly protein 1, mitochondrial142Saccharomyces cerevisiaeMutation(s): 0 
Gene Names: ISU1NUA1YPL135W
UniProt
Find proteins for Q03020 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Explore Q03020 
Go to UniProtKB:  Q03020
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Frataxin homolog, mitochondrial121Saccharomyces cerevisiaeMutation(s): 0 
Gene Names: YFH1YDL120W
EC: 1.16.3.1
UniProt
Find proteins for Q07540 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Explore Q07540 
Go to UniProtKB:  Q07540
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 15.6 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute on Aging (NIH/NIA)United StatesAG15709

Revision History  (Full details and data files)

  • Version 1.0: 2017-06-07
    Type: Initial release
  • Version 1.1: 2017-07-05
    Changes: Database references
  • Version 1.2: 2017-09-13
    Changes: Author supporting evidence, Data collection
  • Version 1.3: 2018-07-18
    Changes: Data collection
  • Version 1.4: 2019-12-18
    Changes: Author supporting evidence