... role of these domains. Rather, the advantageappears to depend on the ability of the lipoyl group toprotrude from the inner core of the complex, indicative of the biological significance of the complex-bound ... a3/310 and a1helices and the length of the a1 helix and (c) the threecharged residues on the thioredoxin surface opposite to the active site, which significantly influence polarization of the molecule. ... reaction substrates and products, (b) kinetic properties of the component enzymes,E1, E2 and E3, and (c) their stoichiometry and interactionswithin the complex. During catalysis in the physiologicaldirection,...