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CATH Superfamily 3.40.50.880

Class I glutamine amidotransferase (GATase) domain

The name of this superfamily has been modified since the most recent official CATH+ release (v4_3_0). At the point of the last release, this superfamily was: waiting to be named.

Functional Families

Overview of the Structural Clusters (SC) and Functional Families within this CATH Superfamily. Clusters with a representative structure are represented by a filled circle.
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FunFam 182: Imidazole glycerol phosphate synthase subunit HisH

There are 2 EC terms in this cluster

Please note: EC annotations are assigned to the full protein sequence rather than individual protein domains. Since a given protein can contain multiple domains, it is possible that some of the annotations below come from additional domains that occur in the same protein, but have been classified elsewhere in CATH.

Note: The search results have been sorted with the annotations that are found most frequently at the top of the list. The results can be filtered by typing text into the search box at the top of the table.

EC Term Annotations Evidence
Glutaminase. [EC: 3.5.1.2]
L-glutamine + H(2)O = L-glutamate + NH(3).
    		 4 A0A371R400 A0A371R400 Q8ZY40 Q8ZY40
    Imidazole glycerol-phosphate synthase. [EC: 4.3.2.10]
    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.
    		 4 A0A371R400 A0A371R400 Q8ZY40 Q8ZY40