Open AccessStructures of native and Fe‐substituted SOD2 from Saccharomyces cerevisiae
Author(s) -
Kang Yan,
He YongXing,
Zhao MengXi,
Li WeiFang
Publication year - 2011
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309111029186
Subject(s) - sod2 , metal , manganese , superoxide , saccharomyces cerevisiae , chemistry , superoxide dismutase , yeast , dismutase , active site , binding site , metal ions in aqueous solution , biophysics , biochemistry , enzyme , biology , organic chemistry
The manganese‐specific superoxide dismutase SOD2 from the yeast Saccharomyces cerevisiae is a protein that resides in the mitochondrion and protects it against attack by superoxide radicals. However, a high iron concentration in the mitochondria results in iron misincorporation at the active site, with subsequent inactivation of SOD2. Here, the crystal structures of SOD2 bound with the native metal manganese and with the `wrong' metal iron are presented at 2.05 and 1.79 Å resolution, respectively. Structural comparison of the two structures shows no significant conformational alteration in the overall structure or in the active site upon binding the non‐native metal iron. Moreover, residues Asp163 and Lys80 are proposed to potentially be responsible for the metal specificity of the Mn‐specific SOD. Additionally, the surface‐potential distribution of SOD2 revealed a conserved positively charged electrostatic zone in the proximity of the active site that probably functions in the same way as in Cu/Zn‐SODs by facilitating the diffusion of the superoxide anion to the metal ion.