label: 5-hydroxy-6-methylpyridine-3,4-dicarboxylate + H(+) <=> 3-hydroxy-2-methylpyridine-5-carboxylate + CO2
label_lc: 5-hydroxy-6-methylpyridine-3,4-dicarboxylate + h(+) <=> 3-hydroxy-2-methylpyridine-5-carboxylate + co2