Term Name:	hydroxymethylbilane synthase activity
Synonyms:	(4-(2-carboxyethyl)-3-(carboxymethyl)pyrrol-2-yl)methyltransferase (hydrolyzing) activity, (4-[2-carboxyethyl]-3-[carboxymethyl]pyrrol-2-yl)methyltransferase (hydrolysing), HMB-synthase activity, porphobilinogen ammonia-lyase (polymerizing), porphobilinogen deaminase activity, porphobilinogen:(4-[2-carboxyethyl]-3-[carboxymethyl]pyrrol-2-yl)methyltransferase (hydrolysing), pre-uroporphyrinogen synthase activity, uroporphyrinogen I synthase activity, uroporphyrinogen I synthetase activity, uroporphyrinogen synthase activity, uroporphyrinogen synthetase activity
Definition:	Catalysis of the reaction: H2O + 4 porphobilinogen = hydroxymethylbilane + 4 NH4.
Ontology:	GO: Molecular Function [GO:0004418]    QuickGO    AmiGO