IUBMB Enzyme Nomenclature


Accepted name: protein N-terminal asparagine amidohydrolase

Reaction: N-terminal L-asparaginyl-[protein] + H2O = N-terminal L-aspartyl-[protein] + NH3

Other name(s): NTAN1 (gene name)

Systematic name: protein N-terminal asparagine amidohydrolase

Comments: This enzyme participates in the eukaryotic ubiquitin-dependent Arg/N-end rule pathway of protein degradation, promoting the turnover of intracellular proteins that initiate with Met-Asn. Following the acetylation and removal of the initiator methionine, the exposed N-terminal asparagine is deaminated, resulting in its conversion to L-aspartate. The latter serves as a substrate for EC, arginyltransferase, making the protein susceptible to arginylation, polyubiquitination and degradation as specified by the N-end rule.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:


1. Stewart, A.E., Arfin, S.M. and Bradshaw, R.A. Protein NH2-terminal asparagine deamidase. Isolation and characterization of a new enzyme. J. Biol. Chem. 269 (1994) 23509-23517. [PMID: 8089117]

2. Grigoryev, S., Stewart, A.E., Kwon, Y.T., Arfin, S.M., Bradshaw, R.A., Jenkins, N.A., Copeland, N.G. and Varshavsky, A. A mouse amidase specific for N-terminal asparagine. The gene, the enzyme, and their function in the N-end rule pathway. J. Biol. Chem. 271 (1996) 28521-28532. [PMID: 8910481]

3. Cantor, J.R., Stone, E.M. and Georgiou, G. Expression and biochemical characterization of the human enzyme N-terminal asparagine amidohydrolase. Biochemistry 50 (2011) 3025-3033. [PMID: 21375249]

[EC created 2016]

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