Premium
dUTP pyrophosphatase is an essential enzyme in Saccharomyces cerevisiae.
Author(s) -
Gadsden M.H.,
McIntosh E.M.,
Game J.C.,
Wilson P.J.,
Haynes R.H.
Publication year - 1993
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1993.tb06127.x
Subject(s) - biology , uracil , saccharomyces cerevisiae , dna glycosylase , dna repair , thymine , biochemistry , dna replication , dna , uracil dna glycosylase , dna damage , mutant , microbiology and biotechnology , yeast , gene
dUTP pyrophosphatase (dUTPase; EC 3.6.1.23) catalyses the hydrolysis of dUTP to dUMP and PPi and thereby prevents the incorporation of uracil into DNA during replication. Although it is widely believed that dUTPase is essential for cell viability because of this role, direct evidence supporting this assumption has not been presented for any eukaryotic system. We have analysed the role of dUTPase (DUT1) in the life cycle of yeast. Using gene disruption and tetrad analysis, we find that DUT1 is necessary for the viability of S. cerevisiae; however, under certain conditions dut1 null mutants survive if supplied with exogenous thymidylate (dTMP). Analyses with isogenic uracil‐DNA‐glycosylase (UNG1) deficient or proficient strains indicate that in the absence of dUTPase, cell death results from the incorporation of uracil into DNA and the attempted repair of this damage by UNG1‐mediated excision repair. However, in dut1 ung1 double mutants, starvation for dTMP causes dividing cells to arrest and die in all phases of the cell cycle. This latter effect suggests that the extensive stable substitution of uracil for thymine in DNA leads to a general failure in macromolecular synthesis. These results are in general agreement with previous models in thymine‐less death that implicate dUTP metabolism. They also suggest an alternative approach for chemotherapeutic drug design.