(1) acetyl-CoA + an N-terminal-L-methionyl-L-alanyl-[protein] = an N-terminal-Nalpha-acetyl-L-methionyl-L-alanyl-[protein] + CoA;
(2) acetyl-CoA + an N-terminal-L-methionyl-L-seryl-[protein] = an N-terminal-Nalpha-acetyl-L-methionyl-L-seryl-[protein] + CoA;
(3) acetyl-CoA + an N-terminal-L-methionyl-L-valyl-[protein] = an N-terminal-Nalpha-acetyl-L-methionyl-L-valyl-[protein] + CoA;
(4) acetyl-CoA + an N-terminal-L-methionyl-L-threonyl-[protein] = an N-terminal-Nalpha-acetyl-L-methionyl-L-threonyl-[protein] + CoA;
(5) acetyl-CoA + an N-terminal-L-methionyl-L-lysyl-[protein] = an N-terminal-Nalpha-acetyl-L-methionyl-L-lysyl-[protein] + CoA;
(6) acetyl-CoA + an N-terminal-L-methionyl-L-leucyl-[protein] = an N-terminal-Nalpha-acetyl-L-methionyl-L-leucyl-[protein] + CoA;
(7) acetyl-CoA + an N-terminal-L-methionyl-L-phenylalanyl-[protein] = an N-terminal-Nalpha-acetyl-L-methionyl-L-phenylalanyl-[protein] + CoA;
(8) acetyl-CoA + an N-terminal-L-methionyl-L-tyrosyl-[protein] = an N-terminal-Nalpha-acetyl-L-methionyl-L-tyrosyl-[protein] + CoA
N-terminal-Nalpha-acetyl-L-methionyl-L-alanyl-[protein];
CoA [CPD:C00010];
N-terminal-Nalpha-acetyl-L-methionyl-L-seryl-[protein];
N-terminal-Nalpha-acetyl-L-methionyl-L-valyl-[protein];
N-terminal-Nalpha-acetyl-L-methionyl-L-threonyl-[protein];
N-terminal-Nalpha-acetyl-L-methionyl-L-lysyl-[protein];
N-terminal-Nalpha-acetyl-L-methionyl-L-leucyl-[protein];
N-terminal-Nalpha-acetyl-L-methionyl-L-phenylalanyl-[protein];
N-terminal-Nalpha-acetyl-L-methionyl-L-tyrosyl-[protein]
Comment
N-terminal-acetylases (NATs) catalyse the covalent attachment of an acetyl moiety from acetyl-CoA to the free alpha-amino group at the N-terminus of a protein. This irreversible modification neutralizes the positive charge at the N-terminus, makes the N-terminal residue larger and more hydrophobic, and prevents its removal by hydrolysis. It may also play a role in membrane targeting and gene silencing. NatE is found in all eukaryotic organisms and plays an important role in chromosome resolution and segregation. It specifically targets N-terminal L-methionine residues attached to Lys, Val, Ala, Tyr, Phe, Leu, Ser, and Thr. There is some substrate overlap with EC 2.3.1.256, N-terminal methionine Nalpha-acetyltransferase NatC. In addition, the acetylation of Met followed by small residues such as Ser, Thr, Ala, or Val suggests a kinetic competition between NatE and EC 3.4.11.18, methionyl aminopeptidase. The enzyme also has the activity of EC 2.3.1.48, histone acetyltransferase, and autoacetylates several of its own lysine residues.
History
EC 2.3.1.258 created 1989 as EC 2.3.1.88, part transferred 2016 to EC 2.3.1.258
N-terminal acetylome analysis reveals the specificity of Naa50 (Nat5) and suggests a kinetic competition between N-terminal acetyltransferases and methionine aminopeptidases.
