CATH Domain 1ah5A03

CATH Classification

Level	CATH Code	Description
	3	Alpha Beta
	3.30	2-Layer Sandwich
	3.30.160	Double Stranded RNA Binding Domain
	3.30.160.40	Porphobilinogen deaminase, C-terminal domain

Domain Context

CATH Clusters

Superfamily	Porphobilinogen deaminase, C-terminal domain
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	1AH5
External Links	PDBSum Proteopedia
Method	X-RAY DIFFRACTION
Organism	Escherichia
Primary Citation	Determination of the structure of seleno-methionine-labelled hydroxymethylbilane synthase in its active form by multi-wavelength anomalous dispersion. Hadener, A., Matzinger, P.K., Battersby, A.R., McSweeney, S., Thompson, A.W., Hammersley, A.P., Harrop, S.J., Cassetta, A., Deacon, A., Hunter, W.N., Nieh, Y.P., Raftery, J., Hunter, N., Helliwell, J.R. Acta Crystallogr.,Sect.D