ID   2.3.1.254
DE   N-terminal methionine N(alpha)-acetyltransferase NatB.
CA   (1) acetyl-CoA + N-terminal L-methionyl-L-asparaginyl-[protein] = CoA +
CA   H(+) + N-terminal N(alpha)-acetyl-L-methionyl-L-asparaginyl-[protein].
CA   (2) acetyl-CoA + N-terminal L-methionyl-L-glutaminyl-[protein] = CoA +
CA   H(+) + N-terminal N(alpha)-acetyl-L-methionyl-L-glutaminyl-[protein].
CA   (3) acetyl-CoA + N-terminal L-methionyl-L-aspartyl-[protein] = CoA + H(+)
CA   + N-terminal N(alpha)-acetyl-L-methionyl-L-aspartyl-[protein].
CA   (4) acetyl-CoA + N-terminal L-methionyl-L-glutamyl-[protein] = CoA + H(+)
CA   + N-terminal N(alpha)-acetyl-L-methionyl-L-glutamyl-[protein].
CC   -!- N-terminal acetylases (NATs) catalyze the covalent attachment of an
CC       acetyl moiety from acetyl-CoA to the free alpha-amino group at the
CC       N-terminus of a protein.
CC   -!- This irreversible modification neutralizes the positive charge at the
CC       N-terminus and makes the N-terminal residue larger and more
CC       hydrophobic, and may also play a role in membrane targeting and gene
CC       silencing.
CC   -!- The NatB complex is found in all eukaryotic organisms,
CC       and specifically targets N-terminal L-methionine residues attached to
CC       Asn, Asp, Gln, or Glu residues at the second position.
CC   -!- Formerly EC 2.3.1.88.
DR   Q8LGI8, NAA20_ARATH;  Q58ED9, NAA20_DANRE;  P61599, NAA20_HUMAN;
DR   Q2PFM2, NAA20_MACFA;  P61600, NAA20_MOUSE;  Q7ZXR3, NAA20_XENLA;
DR   Q6P632, NAA20_XENTR;  O74457, NAT3_SCHPO ;  Q06504, NAT3_YEAST ;
//