CATH Domain 1gtkA03

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	1GTK
External Links	PDBSum Proteopedia
Method	X-RAY DIFFRACTION
Organism
Primary Citation	Time-Resolved and Static-Ensemble Structural Chemistry of Hydroxymethylbilane Synthase Helliwell, J.R., Nieh, Y.P., Habash, J., Faulder, P.F., Raftery, J., Cianci, M., Wulff, M., Hadener, A. Faraday Discuss.