CATH Classification

Domain Context

CATH Clusters

Superfamily Periplasmic binding protein-like II
Functional Family Porphobilinogen deaminase

Enzyme Information

2.5.1.61
Hydroxymethylbilane synthase.
based on mapping to UniProt P06983
4 porphobilinogen + H(2)O = hydroxymethylbilane + 4 NH(3).
-!- The enzyme works by stepwise addition of pyrrolylmethyl groups until a hexapyrrole is present at the active center. -!- The terminal tetrapyrrole is then hydrolyzed to yield the product, leaving a cysteine-bound dipyrrole on which assembly continues. -!- In the presence of a second enzyme, EC 4.2.1.75, which is often called cosynthase, the product is cyclized to form uroporphyrinogen III. -!- If EC 4.2.1.75 is absent, the hydroxymethylbilane cyclizes spontaneously to form uroporphyrinogen I. -!- Formerly EC 4.3.1.8.

UniProtKB Entries (1)

P06983
HEM3_ECOLI
Escherichia coli K-12
Porphobilinogen deaminase

PDB Structure

PDB 1PDA
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
Structure of porphobilinogen deaminase reveals a flexible multidomain polymerase with a single catalytic site.
Louie, G.V., Brownlie, P.D., Lambert, R., Cooper, J.B., Blundell, T.L., Wood, S.P., Warren, M.J., Woodcock, S.C., Jordan, P.M.
Nature