N-alpha-acetyltransferase that acetylates the N-terminus of proteins that retain their initiating methionine (PubMed:25886145). Has a broad substrate specificity: able to acetylate the initiator methionine of most peptides (PubMed:25886145). Non-essential component of the NatA N-terminal acetyltransferase (PubMed:14517307). acetyl-CoA + N-terminal L-methionyl-L-alanyl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-methionyl-L-alanyl-[protein] acetyl-CoA + N-terminal L-methionyl-L-seryl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-methionyl-L-seryl-[protein] acetyl-CoA + N-terminal L-methionyl-L-valyl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-methionyl-L-valyl-[protein] acetyl-CoA + N-terminal L-methionyl-L-threonyl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-methionyl-L-threonyl-[protein] acetyl-CoA + N-terminal L-methionyl-L-lysyl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-methionyl-L-lysyl-[protein] acetyl-CoA + N-terminal L-methionyl-L-leucyl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-methionyl-L-leucyl-[protein] acetyl-CoA + N-terminal L-methionyl-L-phenylalanyl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-methionyl-L-phenylalanyl-[protein] acetyl-CoA + N-terminal L-methionyl-L-tyrosyl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-methionyl-L-tyrosyl-[protein] Component of the N-terminal acetyltransferase A (NatA) complex, which is composed of ARD1, NAT1 and NAT5. Present with 2370 molecules/cell in log phase SD medium. Belongs to the acetyltransferase family.