preferred_name: N(6)-[(R)-lipoyl]-L-lysyl-[dihydrolipoyllysine-residue (2-methylpropanoyl)transferase] + 3-methyl-2-oxobutanoate + H(+) <=> N(6)-[(R)-S(8)-2-methylpropanoyldihydrolipoyl]-L-lysyl-[dihydrolipoyllysine-residue (2-methylpropanoyl)transferase] + CO2