2-oxobutanoate + pyruvate + H(+) <=> (S)-2-ethyl-2-hydroxy-3-oxobutanoate + CO2
2-oxobutanoate + pyruvate + h(+) <=> (s)-2-ethyl-2-hydroxy-3-oxobutanoate + co2
2-oxobutanoate + pyruvate + H(+) <=> (S)-2-ethyl-2-hydroxy-3-oxobutanoate + CO2
2-oxobutanoate + pyruvate + h(+) <=> (s)-2-ethyl-2-hydroxy-3-oxobutanoate + co2