CATH Classification

Domain Context

CATH Clusters

Superfamily Aldolase class I
Functional Family Imidazole glycerol phosphate synthase subunit HisF

Enzyme Information
Imidazole glycerol-phosphate synthase.
based on mapping to UniProt Q7SIB9
5-((5-phospho-1-deoxy-D-ribulos-1-ylamino)methylideneamino)-1-(5-phospho- beta-D-ribosyl)imidazole-4-carboxamide + L-glutamine = 5-amino-1- (5-phospho-beta-D-ribosyl)imidazole-4-carboxamide + D-erythro-1- (imidazol-4-yl)glycerol 3-phosphate + L-glutamate.
-!- The enzyme is involved in histidine biosynthesis, as well as purine nucleotide biosynthesis. -!- The enzymes from archaea and bacteria are heterodimeric. -!- A glutaminase component (cf. EC produces an ammonia molecule that is transferred by a 25 A tunnel to a cyclase component, which adds it to the imidazole ring, leading to lysis of the molecule and cyclization of one of the products. -!- The glutminase subunit is only active within the dimeric complex. -!- In fungi and plants the two subunits are combined into a single polypeptide.

UniProtKB Entries (1)

Thermus thermophilus HB8
Imidazole glycerol phosphate synthase subunit HisF

PDB Structure

External Links
Organism Escherichia
Primary Citation
Structure of imidazole glycerol phosphate synthase from Thermus thermophilus HB8: open-closed conformational change and ammonia tunneling.
Omi, R., Mizuguchi, H., Goto, M., Miyahara, I., Hayashi, H., Kagamiyama, H., Hirotsu, K.