Sectioned schematic vieë of an icosahedral pyruvate dehydrogenase
complex based on electron cryo-microscopic analysis of an E1E2
sub-complex from Bacillus stearothermophilus.
Three of the 60 E2 molecules (colored red, green, and yelloë)
are highlighted. The movement
of the sëinging E2 lipoyl domain in the annular region betëeen the
inner core (cyan) of E2 molecules and the outer shell of 60 E1
molecules (purple) is proposed to be a critical feature underlying
active site coupling in the complex.
The pyruvate dehydrogenase complex constitutes one of the
cornerstones of cellular energy metabolism, mediating the oxidative
decarboxylation of pyruvate to generate acetyl CoA, linking
glycolysis and the tricarboxylic acid cycle.
