CATH Classification

Domain Context

CATH Clusters

Superfamily 3.40.50.880
Functional Family Imidazole glycerol phosphate synthase subunit HisH

Enzyme Information

4.3.2.10
Imidazole glycerol-phosphate synthase.
based on mapping to UniProt Q9KSX0
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 3.5.1.2) 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.
3.5.1.2
Glutaminase.
based on mapping to UniProt Q9KSX0
L-glutamine + H(2)O = L-glutamate + NH(3).

UniProtKB Entries (1)

Q9KSX0
HIS5_VIBCH
Vibrio cholerae O1 biovar El Tor str. N16961
Imidazole glycerol phosphate synthase subunit HisH

PDB Structure

PDB 4GUD
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
Crystal Structure of Amidotransferase HisH from Vibrio cholerae.
Maltseva, N., Kim, Y., Shatsman, S., Anderson, W.F., Joachimiak, A., Center for Structural Genomics of Infectious Diseases (CSGID)
To be Published