(2R)-2-hydroxy-4-(methylsulfanyl)butanoate + NAD(+) <=> 4-methylsulfanyl-2-oxobutanoate + NADH + H(+)
(2r)-2-hydroxy-4-(methylsulfanyl)butanoate + nad(+) <=> 4-methylsulfanyl-2-oxobutanoate + nadh + h(+)
(2R)-2-hydroxy-4-(methylsulfanyl)butanoate + NAD(+) <=> 4-methylsulfanyl-2-oxobutanoate + NADH + H(+)
(2r)-2-hydroxy-4-(methylsulfanyl)butanoate + nad(+) <=> 4-methylsulfanyl-2-oxobutanoate + nadh + h(+)