Structure-based hypothesis on the activation of the CO-sensing transcription factor CooA

The structure of a CooA variant from the thermophilic bacterium Carboxydothermus hydrogenoformans (ChCooA) is reported in which one monomer is fully in the on-state.

Photoreduction of the active site of the metalloprotein putidaredoxin by synchrotron radiation

Single-crystal X-ray absorption spectroscopy (XAS) is used to show the temperature-dependence of X-ray photoreduction of the active site of putidaredoxin, an iron-containing metalloprotein, in a study that highlights the importance of using liquid-helium-based cooling during metalloprotein crystallography experiments and the utility of simultaneous XAS measurements.