5n56

Publication Abstract from PubMed

The 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^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.