hydroxymethylbilane + 4 NH4(+) => 4 porphobilinogen + H2O
hydroxymethylbilane + 4 nh4(+) => 4 porphobilinogen + h2o
hydroxymethylbilane + 4 NH4(+) => 4 porphobilinogen + H2O
hydroxymethylbilane + 4 nh4(+) => 4 porphobilinogen + h2o