Rieske Protein from Thermus thermophilus: 15N NMR Titration Study Demonstrates the Role of Iron-Ligated Histidines in the pH Dependence of the Reduction Potential.

The article discusses the study that demonstrates the role of iron-ligated histidines in the pH dependence of the reduction potential. The researchers recorded a 15N NMR spectra of oxidized Rieke iron—sulfur protein from Thermus thermophilis as function of pH. Direct evidence for sequential dissociation of protons from N∈2 atoms of the two iron-coordinated histidine rings in the oxidized protein has been provided by the data.