Actinobacteria challenge the paradigm: A unique protein architecture for a well-known, central metabolic complex
Eduardo M. Bruch, Pierre Vilela, Lu Yang, Alexandra Boyko, Norik Lexa-Sapart, Bertrand Raynal, Pedro M. Alzari, Marco Bellinzoni
Abstract
Significance α-oxoacid dehydrogenase are large, evolutionary-conserved multienzymatic complexes that carry out key oxidative reactions in central metabolism. For decades, these complexes were thought to share a similar organization in all aerobic organisms, structured around a hollow core resulting from the high oligomeric arrangement of the acyltransferase component. Here, we show that Actinobacteria, one of the largest eubacterial phyla, break this “dogma” owing to a distinct trimeric acyltransferase core. We provide a structural explanation to this different oligomeric architecture and show how this feature, related to a fusion of two genes coding for 2-oxoglutarate dehydrogenase, constitutes a trait of Actinobacteria providing a different perspective on the evolution of these metabolic complexes.