3QQD : Human SOD1 H80R variant, P212121 crystal form

  • Sai V. Seetharaman (Contributor)
  • Duane D. Winkler (Contributor)
  • Alexander Bryan Taylor (Contributor)
  • Xiaohang Cao (Contributor)
  • Lisa J. Whitson (Contributor)
  • Peter A. Doucette (Contributor)
  • Joan S. Valentine (Contributor)
  • Virgil Schirf (Contributor)
  • Borries Demeler (Department of Biochemistry) (Contributor)
  • Mark C. Carroll (Contributor)
  • Valeria C. Culotta (Contributor)
  • P. John Hart (Department of Biochemistry, Department of Veterans Affairs) (Contributor)



Experimental Technique/Method:X-RAY DIFFRACTION
Release Date:2011-03-09
Deposition Date:2011-02-15
Revision Date:2011-07-13
Molecular Weight:32132.24
Macromolecule Type:Protein
Residue Count:308
Atom Site Count:1840

Mutations in human copper-zinc superoxide dismutase (SOD1) cause an inherited form of the fatal neurodegenerative disease amyotrophic lateral sclerosis (ALS). Here, we present structures of the pathogenic SOD1 variants D124V and H80R, both of which demonstrate compromised zinc-binding sites. The disruption of the zinc-binding sites in H80R SOD1 leads to conformational changes in loop elements, permitting non-native SOD1-SOD1 interactions that mediate the assembly of these proteins into higher-order filamentous arrays. Analytical ultracentrifugation sedimentation velocity experiments indicate that these SOD1 variants are more prone to monomerization than the wild-type enzyme. Although D124V and H80R SOD1 proteins appear to have fully functional copper-binding sites, inductively coupled plasma mass spectrometery (ICP-MS) and anomalous scattering X-ray diffraction analyses reveal that zinc (not copper) occupies the copper-binding sites in these variants. The absence of copper in these proteins, together with the results of covalent thiol modification experiments in yeast strains with and without the gene encoding the copper chaperone for SOD1 (CCS), suggests that CCS may not fully act on newly translated forms of these polypeptides. Overall, these findings lend support to the hypothesis that immature mutant SOD1 species contribute to toxicity in SOD1-linked ALS.
Date made available2011

Cite this