2NNX
Crystal Structure of the H46R, H48Q double mutant of human [Cu-Zn] Superoxide Dismutase
Summary for 2NNX
| Entry DOI | 10.2210/pdb2nnx/pdb |
| Descriptor | SUPEROXIDE DISMUTASE [CU-ZN], ZINC ION, SULFATE ION, ... (4 entities in total) |
| Functional Keywords | oxidoreductase; human; cu-zn superoxide dismutase; superoxide acceptor; familial amyotrophic lateral sclerosis mutant, oxidoreductase |
| Biological source | Homo sapiens (human) |
| Total number of polymer chains | 4 |
| Total formula weight | 64069.85 |
| Authors | Schuermann, J.P.,Hart, P.J. (deposition date: 2006-10-24, release date: 2006-11-07, Last modification date: 2024-11-13) |
| Primary citation | Wang, J.,Caruano-Yzermans, A.,Rodriguez, A.,Scheurmann, J.P.,Slunt, H.H.,Cao, X.,Gitlin, J.,Hart, P.J.,Borchelt, D.R. Disease-associated mutations at copper ligand histidine residues of superoxide dismutase 1 diminish the binding of copper and compromise dimer stability J.Biol.Chem., 282:345-352, 2007 Cited by PubMed Abstract: A subset of superoxide dismutase 1 (Cu/Zn-SOD1) mutants that cause familial amyotrophic lateral sclerosis (FALS) have heightened reactivity with (-)ONOO and H(2)O(2) in vitro. This reactivity requires a copper ion bound in the active site and is a suggested mechanism of motor neuron injury. However, we have found that transgenic mice that express SOD1-H46R/H48Q, which combines natural FALS mutations at ligands for copper and which is inactive, develop motor neuron disease. Using a direct radioactive copper incorporation assay in transfected cells and the established tools of single crystal x-ray diffraction, we now demonstrate that this variant does not stably bind copper. We find that single mutations at copper ligands, including H46R, H48Q, and a quadruple mutant H46R/H48Q/H63G/H120G, also diminish the binding of radioactive copper. Further, using native polyacrylamide gel electrophoresis and a yeast two-hybrid assay, the binding of copper was found to be related to the formation of the stable dimeric enzyme. Collectively, our data demonstrate a relationship between copper and assembly of SOD1 into stable dimers and also define disease-causing SOD1 mutants that are unlikely to robustly produce toxic radicals via copper-mediated chemistry. PubMed: 17092942DOI: 10.1074/jbc.M604503200 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.3 Å) |
Structure validation
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