Gcn5-related N-acetyltransferase (GNAT) domain, ATAT-type (IPR007965)

Short name: GNAT_ATAT

Overlapping homologous superfamilies


Domain relationships



The N-acetyltransferases (NAT) (EC 2.3.1.-) are enzymes that use acetyl coenzyme A (CoA) to transfer an acetyl group to a substrate, a reaction implicated in various functions from bacterial antibiotic resistance to mammalian circadian rhythm and chromatin remodeling. The Gcn5-related N-acetyltransferases (GNAT) catalyze the transfer of the acetyl from the CoA donor to a primary amine of the acceptor. The GNAT proteins share a domain composed of four conserved sequence motifs A-D [PMID: 9175471, PMID: 10940244]. This GNAT domain is named after yeast GCN5 (from General Control Nonrepressed) and related histone acetyltransferases (HATs) like Hat1 and PCAF. HATs acetylate lysine residues of amino terminal histone tails, resulting in transcription activation. Another category of GNAT, the aminoglycoside N-acetyltransferases, confer antibiotic resistance by catalyzing the acetylation of amino groups in aminoglycoside antibiotics [PMID: 12592013]. GNAT proteins can also have anabolic and catabolic functions in both prokaryotes and eukaryotes [PMID: 9175471, PMID: 10940244, PMID: 12592013, PMID: 12527305, PMID: 15581578].

The acetyltransferase/GNAT domain forms a structurally conserved fold of 6 to 7 beta strands (B) and 4 helices (H) in the topology B1-H1-H2-B2-B3-B4-H3-B5-H4-B6, followed by a C-terminal strand which may be from the same monomer or contributed by another [PMID: 10940244, PMID: 15581578]. Motifs D (B2-B3), A (B4-H3) and B (B5-H4) are collectively called the HAT core [PMID: 10940244, PMID: 12527305, PMID: 15581578], while the N-terminal motif C (B1-H1) is less conserved.

This entry represents the ATAT-type of the GNAT domain [PMID: 23894642]. Proteins containing this domain include alpha-tubulin N-acetyltransferase, originally known as mechanosensory abnormality protein 17 (Mec-17), as it is the protein product of one of the 18 genes required for the development and function of the touch receptor neuron for gentle touch [PMID: 12124626]. Mec-17 specifically acetylates 'Lys-40' in alpha-tubulin on the lumenal side of microtubules [PMID: 20829795]. It is inefficient, and its activity is enhanced when tubulin is incorporated in microtubules [PMID: 23105108]. It may affect microtubule stability and regulate microtubule dynamics.

GO terms

Biological Process

GO:0071929 alpha-tubulin acetylation

Molecular Function

GO:0019799 tubulin N-acetyltransferase activity

Cellular Component

GO:0005874 microtubule

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE profiles