Protein N-terminal glutamine amidohydrolase (NTAQ1)

Protein N-terminal glutamine amidohydrolase (NTAQ1) is a monomeric enzyme involved in the N-end rule pathway of protein degradation. It catalyzes the deamidation of N-terminal glutamine residues to produce glutamate, a reaction necessary for subsequent arginylation, polyubiquitination, and degradation of the substrate protein. NTAQ1 has a unique alpha-beta-alpha sandwich architecture with a conserved catalytic triad (Cys-His-Asp) in its active site. The enzyme is highly specific for N-terminal glutamine and does not act on internal, C-terminal, or acetylated N-terminal glutamine residues. Its activity is central to the regulation of protein half-life in eukaryotic cells, and mutations or dysfunctions in its human or animal homologs have been linked to cancer and neurological conditions.

Other names

C8orf32WDYHV1N-terminal Gln amidaseNt(Q)-amidaseFLJ10204Protein NH2-terminal glutamine deamidaseWDYHV motif-containing protein 1WDYHV motif containing 1

Enzyme inhibition (experimental): thiol-specific reagents such as iodoacetamide and N-ethylmaleimide inhibit NTAQ1 in vitro.