ID 4.2.1.75 DE uroporphyrinogen-III synthase. AN hydroxymethylbilane hydro-lyase (cyclizing). AN uroporphyrinogen-III cosynthase. AN uroporphyrinogen-III cosynthetase. CA hydroxymethylbilane = H2O + uroporphyrinogen III. CC -!- In the presence of EC 2.5.1.61, forms uroporphyrinogen III from CC porphobilinogen. DR O48721, HEM4_ARATH ; O30120, HEM4_ARCFU ; P21248, HEM4_BACSU ; DR Q59335, HEM4_CHLP8 ; Q8KCJ3, HEM4_CHLTE ; P09126, HEM4_ECOLI ; DR P10746, HEM4_HUMAN ; Q58401, HEM4_METJA ; O26268, HEM4_METTH ; DR P51163, HEM4_MOUSE ; Q10QR9, HEM4_ORYSJ ; Q59683, HEM4_PROMI ; DR P48246, HEM4_PSEAE ; Q59294, HEM4_RUMJO ; Q9L6Q3, HEM4_SALTY ; DR P87214, HEM4_SCHPO ; P42452, HEM4_SYNE7 ; P06174, HEM4_YEAST ; //