TABLE 1.
The five types of yeast N-terminal acetyltransferases
| NAT type | Catalytic subunit | Auxiliary subunit(s) | Substratesc | No. of substrates |
|---|---|---|---|---|
| NatA | Ard1a | Nat1a,b | Ser, Ala, Gly, Thy | >2,000 |
| NatB | Nat3a | Mdm20a | Met-Glu, Met-Asp, Met-Asn, Met-Met | >600 |
| NatC | Mak3a | Mak10,a Mak31 | Met-Ile, Met-Leu, Met-Trp, Met-Phe | Low |
| NatD | Nat4a | Ser-Gly-Gly-Lys, Ser-Gly-Arg-Gly | At least 2 | |
| NatE | Nat5a | Nat1a,b | Unknown | Unknown |
a
Subunits that were shown to be associated with ribosomes.
b
We suggest that the auxiliary subunit Nat1p is common to both NatA and NatE and that nat1-Δ mutants are deficient in both acetyltransferases.
c
Acetylation occurs only on subclasses of proteins containing the indicated termini, except for Met-Glu and Met-Asp termini, which are apparently always acetylated.