[SEMINAR] Conformational mechanism of CO2 fixation in the bifunctional complex carbon monoxide dehydrogenase / acetyl-CoA synthase

Title: Conformational mechanism of CO2 fixation in the bifunctional complex carbon monoxide dehydrogenase / acetyl-CoA synthase 

Speaker: Bonnie Murphy 

From: Max Planck Institute of Biophysics, Frankfurt

Abstract: The Wood-Ljungdahl pathway is a highly efficient pathway for CO₂ fixation used by anaerobic bacteria and archaea, which is responsible for around 20% of global annual CO₂ fixation. In this pathway, a single complex catalyzes both the reduction of CO₂ to CO, and its subsequent reaction with a methyl group and coenzyme A to generate acetyl-CoA. Previous studies have shown that the complex is highly dynamic, but an understanding of many steps of the mechanism was missing. By preparing samples under anaerobic conditions, under CO, and in the presence of electron- and methyl- donor partner proteins, we have resolved a conformational storyline that allows us to understand how domain-scale rearrangements mediate the steps of CO₂ fixation in this complex, and how its unique metallocofactors catalyze the challenging reactions required.  

Speaker Bio: Bonnie Murphy received her PhD in Chemistry from the University of Oxford under the guidance of Fraser Armstrong. She carried out postdoctoral work at the Max Planck Institute of Biophysics in the department of Structural Biology under the supervision of Werner Kühlbrandt. Since 2020, she leads an independent research group at the MPI of Biophysics in Frankfurt. Her work has spanned structural, electrochemical and spectroscopic investigations of redox proteins and other bioenergetic complexes. In addition to applying the tools of cryo-EM to understand bioenergetic processes, her group works to further develop the methods of cryo-EM to characterize elemental distributions in dose-sensitive cryo-preserved samples. More information.