Download MendeleyThe Structure of Human Mitochondrial Mn3+ Superoxide Dismutase Reveals a Novel Tetrameric Interface of Two 4-Helix Bundles
Borgstahl, G.E., Parge, H.E., Hickey, M.J., Beyer Jr., W.F., Hallewell, R.A., Tainer, J.A.(1992) Cell 71: 107-107
- PubMed: 1394426
- DOI: https://doi.org/10.1016/0092-8674(92)90270-m
- Primary Citation of Related Structures:
1N0J - PubMed Abstract:
The 2.2 A resolution crystal structure of recombinant human manganese superoxide dismutase, a homotetrameric enzyme that protects mitochondria against oxygen-mediated free radical damage, has been determined. Within each subunit, both the N-terminal helical hairpin and C-terminal alpha/beta domains contribute ligands to the catalytic manganese site. Two identical 4-helix bundles, symmetrically assembled from the N-terminal helical hairpins, form novel tetrameric interfaces that stabilize the active sites. Structurally altered polymorphic variants with reduced activity, such as tetrameric interface mutant Ile-58 to Thr, may produce not only an early selective advantage, through enhanced cytotoxicity of tumor necrosis factor for virus-infected cells, but also detrimental effects from increased mitochondrial oxidative damage, contributing to degenerative conditions, including diabetes, aging, and Parkinson's and Alzheimer's diseases.
Organizational Affiliation:
Department of Molecular Biology, Scripps Research Institute, La Jolla, California 92037.
