Uroporphyrinogen-III synthase (UROS)

Catalyzes cyclization of the linear tetrapyrrole, hydroxymethylbilane, to the macrocyclic uroporphyrinogen III, the branch point for the various sub-pathways resulting in the broad diversity of porphyrins. Porphyrins act as cofactors for a multitude of enzymes that perform an assortment of processes within the cell such as methionine synthesis (vitamin B12) or oxygen transport (heme).

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