NatC N-alpha-terminal acetyltransferase of yeast contains three subunits, Mak3p, Mak10p, and Mak31p

The yeast Saccharomyces cerevisiae contains three types of N-alpha-terminal acetyltransferases, NatA, NatB, and NatC, with each having a different cat alytic subunit, Ard1p, Nat3p, and Mak3p, respectively, and each acetylating different sets of proteins with different N-alpha-terminal regions. We sho w that the NatC N-alpha-terminal acetyltransferases contains Mak10p and Mak 31p subunits, in addition to Mak3p, and that all three subunits are associa ted with each other to form the active complex. Genetic deletion of any one of the three subunits results in identical abnormal phenotypes, including the lack of acetylation of a NatC substrate in vivo, diminished growth at 3 7 degreesC on media containing nonfermentable carbon sources, and the lack of maintenance or assembly of the L-A dsRNA viral particle.