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Architecture of the Yeast Mitochondrial Iron-Sulfur Cluster Assembly Machinery: The Sub-Complex Formed by the Iron Donor, Yfh1, and the Scaffold, Isu1.

Ranatunga, Wasantha; Gakh, Oleksandr; Galeano, Belinda K; Smith, Douglas Y; Söderberg, Christopher LU ; Al-Karadaghi, Salam LU ; Thompson, James R and Isaya, Grazia (2016) In Journal of Biological Chemistry 291(19). p.10378-10398
Abstract
The biosynthesis of Fe-S clusters is a vital process involving the delivery of elemental iron and sulfur to scaffold proteins via molecular interactions that are still poorly defined. We reconstituted a stable, functional complex consisting of the iron donor, Yfh1, and the Fe-S cluster scaffold, Isu1, with 1:1 stoichiometry, [Yfh1]24 ·: [Isu1]24. Using negative staining transmission EM and single particle analysis, we obtained a three-dimensional reconstruction of this complex at a resolution of ~17 Å. In addition, via chemical cross-linking, limited proteolysis and mass spectrometry we identified protein-protein interaction surfaces within the complex. The data together reveal that [Yfh1]24 ·: [Isu1]24 is a roughly cubic macromolecule... (More)
The biosynthesis of Fe-S clusters is a vital process involving the delivery of elemental iron and sulfur to scaffold proteins via molecular interactions that are still poorly defined. We reconstituted a stable, functional complex consisting of the iron donor, Yfh1, and the Fe-S cluster scaffold, Isu1, with 1:1 stoichiometry, [Yfh1]24 ·: [Isu1]24. Using negative staining transmission EM and single particle analysis, we obtained a three-dimensional reconstruction of this complex at a resolution of ~17 Å. In addition, via chemical cross-linking, limited proteolysis and mass spectrometry we identified protein-protein interaction surfaces within the complex. The data together reveal that [Yfh1]24 ·: [Isu1]24 is a roughly cubic macromolecule consisting of one symmetric Isu1 trimer binding on top of one symmetric Yfh1 trimer at each of its eight vertices. Furthermore, molecular modeling suggests that two subunits of the cysteine desulfurase, Nfs1, may bind symmetrically on top of two adjacent Isu1 trimers in a manner that creates two putative [2Fe-2S] cluster assembly centers. In each center, conserved amino acids known to be involved in sulfur and iron donation by Nfs1 and Yfh1, respectively, are in close proximity to the Fe-S cluster coordinating residues of Isu1. We suggest that this architecture is suitable to ensure concerted and protected transfer of potentially toxic iron and sulfur atoms to Isu1 during Fe-S cluster assembly. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Biological Chemistry
volume
291
issue
19
pages
10378 - 10398
publisher
ASBMB
external identifiers
  • pmid:26941001
  • scopus:84966319172
  • wos:000375602800043
ISSN
1083-351X
DOI
10.1074/jbc.M115.712414
language
English
LU publication?
yes
id
512e1ed7-59ba-4546-ba1e-17cefd2c63a7 (old id 8856287)
date added to LUP
2016-03-21 08:52:50
date last changed
2017-09-24 03:02:56
@article{512e1ed7-59ba-4546-ba1e-17cefd2c63a7,
  abstract     = {The biosynthesis of Fe-S clusters is a vital process involving the delivery of elemental iron and sulfur to scaffold proteins via molecular interactions that are still poorly defined. We reconstituted a stable, functional complex consisting of the iron donor, Yfh1, and the Fe-S cluster scaffold, Isu1, with 1:1 stoichiometry, [Yfh1]24 ·: [Isu1]24. Using negative staining transmission EM and single particle analysis, we obtained a three-dimensional reconstruction of this complex at a resolution of ~17 Å. In addition, via chemical cross-linking, limited proteolysis and mass spectrometry we identified protein-protein interaction surfaces within the complex. The data together reveal that [Yfh1]24 ·: [Isu1]24 is a roughly cubic macromolecule consisting of one symmetric Isu1 trimer binding on top of one symmetric Yfh1 trimer at each of its eight vertices. Furthermore, molecular modeling suggests that two subunits of the cysteine desulfurase, Nfs1, may bind symmetrically on top of two adjacent Isu1 trimers in a manner that creates two putative [2Fe-2S] cluster assembly centers. In each center, conserved amino acids known to be involved in sulfur and iron donation by Nfs1 and Yfh1, respectively, are in close proximity to the Fe-S cluster coordinating residues of Isu1. We suggest that this architecture is suitable to ensure concerted and protected transfer of potentially toxic iron and sulfur atoms to Isu1 during Fe-S cluster assembly.},
  author       = {Ranatunga, Wasantha and Gakh, Oleksandr and Galeano, Belinda K and Smith, Douglas Y and Söderberg, Christopher and Al-Karadaghi, Salam and Thompson, James R and Isaya, Grazia},
  issn         = {1083-351X},
  language     = {eng},
  month        = {03},
  number       = {19},
  pages        = {10378--10398},
  publisher    = {ASBMB},
  series       = {Journal of Biological Chemistry},
  title        = {Architecture of the Yeast Mitochondrial Iron-Sulfur Cluster Assembly Machinery: The Sub-Complex Formed by the Iron Donor, Yfh1, and the Scaffold, Isu1.},
  url          = {http://dx.doi.org/10.1074/jbc.M115.712414},
  volume       = {291},
  year         = {2016},
}