5n57 | pdb_00005n57
Staphylococcus aureus cambialistic superoxide dismutase SodM
Structural highlights
FunctionSODM2_STAA8 Destroys superoxide anion radicals which are normally produced within the cells and which are toxic to biological systems. Catalyzes the dismutation of superoxide anion radicals into O2 and H2O2 by successive reduction and oxidation of the transition metal ion at the active site. May play a role in maintaining cell viability during the late-exponential and stationary phases of growth since it becomes a major source of activity under oxidative stress. Has a role in resisting external superoxide stress. Involved in acid tolerance and the acid-adaptive response. Mediates the derepression of perR regulon in the response to HOCl stress at low level of SOD activity (By similarity).[1] [2] Publication Abstract from PubMedThe pathogenicity of Staphylococcus aureus is enhanced by having two superoxide dismutases (SODs): a Mn-specific SOD and another that can use either Mn or Fe. Using 94 GHz electron-nuclear double resonance (ENDOR) and electron double resonance detected (ELDOR)-NMR we show that, despite their different metal-specificities, their structural and electronic similarities extend down to their active-site (1)H- and (14)N-Mn(ii) hyperfine interactions. However these interactions, and hence the positions of these nuclei, are different in the inactive Mn-reconstituted Escherichia coli Fe-specific SOD. Density functional theory modelling attributes this to a different angular position of the E. coli H171 ligand. This likely disrupts the Mn-H171-E170' triad causing a shift in charge and in metal redox potential, leading to the loss of activity. This is supported by the correlated differences in the Mn(ii) zero-field interactions of the three SOD types and suggests that the triad is important for determining metal specific activity. A charge polarization model for the metal-specific activity of superoxide dismutases.,Barwinska-Sendra A, Basle A, Waldron KJ, Un S Phys Chem Chem Phys. 2018 Jan 24;20(4):2363-2372. doi: 10.1039/c7cp06829h. PMID:29308487[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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