Identification and characterization of genes and mutants for an N-terminal acetyltransferase from yeast.
A gene from Saccharomyces cerevisiae has been mapped, cloned, sequenced and shown to encode a catalytic subunit of an N-terminal acetyltransferase. Regions of this gene, NAT1, and the chloramphenicol acetyltransferase genes of bacteria have limited but significant homology. A nat1 null mutant is viable but exhibits a variety of phenotypes, including reduced acetyltransferase activity, derepression of a silent mating type locus (HML) and failure to enter G0. All these phenotypes are identical to those of a previously characterized mutant, ard1. NAT1 and ARD1 are distinct genes that encode proteins with no obvious similarity. Concomitant overexpression of both NAT1 and ARD1 in yeast causes a 20-fold increase in acetyltransferase activity in vitro, whereas overexpression of either NAT1 or ARD1 alone does not raise activity over basal levels. A functional iso-1-cytochrome c protein, which is N-terminally acetylated in a NAT1 strain, is not acetylated in an isogenic nat1 mutant. At least 20 other yeast proteins, including histone H2B, are not N-terminally acetylated in either nat1 or ard1 mutants. These results suggest that NAT1 and ARD1 proteins function together to catalyze the N-terminal acetylation of a subset of yeast proteins.
Mullen
J R
JR
Department of Biochemistry, State University of New York, Stony Brook 11794.
Kayne
P S
PS
Moerschell
R P
RP
Tsunasawa
S
S
Gribskov
M
M
Colavito-Shepanski
M
M
Grunstein
M
M
Sherman
F
F
Sternglanz
R
R
D000123:Acetyltransferases / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D003574:Cytochrome c Group / Q000235:genetics; D045304:Cytochromes c; D005796:Genes; D005800:Genes, Fungal; D049770:Genes, Mating Type, Fungal; D006657:Histones / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D063209:N-Terminal Acetyltransferase A; D010641:Phenotype; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D012689:Sequence Homology, Nucleic Acid
C014059:CYC1 protein, S cerevisiae; D003574:Cytochrome c Group; D006657:Histones; C540859:NAT1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D045304:Cytochromes c; D000123:Acetyltransferases; C061313:protein N-terminal acetyltransferase; D063209:N-Terminal Acetyltransferase A; C540858:ARD1 protein, S cerevisiae