2HES: Cytosolic Iron-sulphur Assembly Protein- 1

The WD40-repeat protein Cia1 is an essential, conserved member of the cytosolic iron-sulfur (Fe/S) protein assembly (CIA) machinery in eukaryotes. Here, we report the crystal structure of Saccharomyces cerevisiae Cia1 to 1.7 A resolution. The structure folds into a beta propeller with seven blades pseudo symmetrically arranged around a central axis. Structure-based sequence alignment of Cia1 proteins shows that the WD40 propeller core elements are highly conserved. Site-directed mutagenesis of amino acid residues in loop regions with high solvent accessibility identified that the conserved top surface residue R127 performs a critical function: the R127 mutant cells grew slowly and were impaired in cytosolic Fe/S protein assembly. Human Ciao1, which reportedly interacts with the Wilms' tumor suppressor, WT1, is structurally similar to yeast Cia1. We show that Ciao1 can functionally replace Cia1 and support cytosolic Fe/S protein biogenesis. Hence, our structural and biochemical studies indicate the conservation of Cia1 function in eukaryotes.
PDB ID: 2HESDownload
MMDB ID: 47128
PDB Deposition Date: 2006/6/22
Updated in MMDB: 2007/11
Experimental Method:
x-ray diffraction
Resolution: 1.7  Å
Source Organism:
Similar Structures:
Biological Unit for 2HES: monomeric; determined by author
Molecular Components in 2HES
Label Count Molecule
Protein (1 molecule)
Ydr267cp(Gene symbol: CIA1)
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

Citing MMDB