Catalytic component of the NatA N-terminal acetyltransferase, which catalyzes acetylation of proteins beginning with Met-Ser, Met-Gly and Met-Ala. N-acetylation plays a role in normal eukaryotic translation and processing, protect against proteolytic degradation and protein turnover. acetyl-CoA + N-terminal glycyl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetylglycyl-[protein] acetyl-CoA + N-terminal L-alanyl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-alanyl-[protein] acetyl-CoA + N-terminal L-seryl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-seryl-[protein] acetyl-CoA + N-terminal L-valyl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-valyl-[protein] acetyl-CoA + N-terminal L-cysteinyl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-cysteinyl-[protein] acetyl-CoA + N-terminal L-threonyl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-threonyl-[protein] Component of the N-terminal acetyltransferase A (NatA) complex, which is composed of ARD1, NAT1 and NAT5. Can self-associate. Present with 3310 molecules/cell in log phase SD medium. Belongs to the acetyltransferase family. ARD1 subfamily.