In enzymology, an alpha-tubulin N-acetyltransferase () is an enzyme which is encoded by the ATAT1 gene. This enzyme belongs to the family of transferases, specifically those acyltransferases transferring groups other than aminoacyl groups. The systematic name of this enzyme class is acetyl-CoA:[alpha-tubulin]-L-lysine N6-acetyltransferase. Other names in common use include alpha-tubulin acetylase, αTAT, ATAT1, TAT, alpha-TAT, alpha-tubulin acetyltransferase, tubulin N-acetyltransferase, acetyl-CoA:alpha-tubulin-L-lysine N-acetyltransferase, and acetyl-CoA:[alpha-tubulin]-L-lysine 6-N-acetyltransferase. Structure Primary This protein has a length of 421 amino acids, among which, we have to highlight the Glutamine number 58 (Gln or Q), which is crucial for catalytic activity. Secondary ATAT1 has 8 α-helix, 10 β-strands and one turn. However, only half of the protein has a defined secondary conformation. The rest of this protein is intrinsically disordered. Domains ATAT1 it is not a modular protein because it only have one domain localized from the first amino acid to the one hundred and ninety. Regions It must be highlighted two important regions of ATAT1 (124-137 and 160-269), because is here where junction points with Acetyl-coA are. Recently, studies describing the crystal structure of ATAT1 suggest that residues 196 to 236 of human ATAT1 (where acetylated lysines K210 and K221 are located) are disordered and do not contribute significantly to catalytic activity. In contrast, acetylated residues K56 and K146 are both within the catalytic domain (α1 and α3 helices, respectively) and close to the Acetyl CoA binding site, which suggests that these residues might act as an intermediate for the transfer of the acetyl group. However, further structural data with autoacetylation mutants are needed to fully understand this mechanism and to test the possibility of conformational changes caused by ATAT1 autoacetylation. Active site ATAT1 contains a conserved surface pocket close to the active site composed largely of hydrophobic and basic residues, which likely complement the acidic loop containing α-tubulin K40. The protein's active site contains several conserved residues that could potentially function as general bases in the reaction: glutamine 58 (Q58), cysteine (C120), and aspartic acid 157 (D157). Isoforms ATAT1 presents seven different isoforms due to alternative splicing, a process which consists in the combination of exons during the end of the transcription process. Consequently, from a single gene more tan one messenger RNA can be produced. The different isoforms are: Isoform 1 Isoform 1 is known as the canonical sequence. This means that the changes in the other isoforms will be related to this particular