Porphobilinogen synthase (or ALA dehydratase, or aminolevulinate dehydratase) synthesizes porphobilinogen through the asymmetric condensation of two molecules of aminolevulinic acid. All natural tetrapyrroles, including hemes, chlorophylls and vitamin B12, share porphobilinogen as a common precursor.
It catalyzes the second step of the biosynthesis of porphyrin. The porphobilinogen synthase catalyzed reaction is the first common step in the biosynthesis of all biological tetrapyrroles.
Porphobilinogen synthase is the prototype morpheein.
Read more about Porphobilinogen Synthase: Deficiency