1uro
UROPORPHYRINOGEN DECARBOXYLASE
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OverviewOverview
Uroporphyrinogen decarboxylase (URO-D) catalyzes the fifth step in the heme biosynthetic pathway, converting uroporphyrinogen to coproporphyrinogen by decarboxylating the four acetate side chains of the substrate. This activity is essential in all organisms, and subnormal activity of URO-D leads to the most common form of porphyria in humans, porphyria cutanea tarda (PCT). We have determined the crystal structure of recombinant human URO-D at 1.60 A resolution. The 40.8 kDa protein is comprised of a single domain containing a (beta/alpha)8-barrel with a deep active site cleft formed by loops at the C-terminal ends of the barrel strands. Many conserved residues cluster at this cleft, including the invariant side chains of Arg37, Arg41 and His339, which probably function in substrate binding, and Asp86, Tyr164 and Ser219, which may function in either binding or catalysis. URO-D is a dimer in solution (Kd = 0.1 microM), and this dimer also appears to be formed in the crystal. Assembly of the dimer juxtaposes the active site clefts of the monomers, suggesting a functionally important interaction between the catalytic centers.
DiseaseDisease
Known diseases associated with this structure: Porphyria cutanea tarda OMIM:[176100], Porphyria, hepatoerythropoietic OMIM:[176100]
About this StructureAbout this Structure
1URO is a Single protein structure of sequence from Homo sapiens with as ligand. Active as Uroporphyrinogen decarboxylase, with EC number 4.1.1.37 Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of human uroporphyrinogen decarboxylase., Whitby FG, Phillips JD, Kushner JP, Hill CP, EMBO J. 1998 May 1;17(9):2463-71. PMID:9564029
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