Incision and postincision steps of pyrimidine dimer removal in excision-defective mutants of Saccharomyces cerevisiae

Journal Article · Sun Nov 01 04:00:00 EST 1981 · J. Bacteriol.; (United States)

OSTI ID:5631968

Wilcox, D R; Prakash, L

cdc9, a temperature-sensitive mutant defective in polynucleotide deoxyribonucleic acid (DNA) ligase activity, accumulates low-molecular-weight DNA fragments (as measured by sedimentation of DNA in alkaline sucrose gradients) at the nonpermissive temperature after irradiation with ultraviolet light. This phenotype of cdc9 is a sensitive indicator of successful incision during excision repair of dimers. In strains containing excision-defective mutations in any of nine genes in combination with the cdc9 mutation, the absence of low-molecular-weight DNA at the nonpermissive temperature after ultraviolet treatment suggests that these mutants are incision defective, whereas the presence of low-molecular-weight DNA indicates that the mutants are defective in a step after incision. With rad1, rad2, rad3, rad4, and rad10 mutants, the molecular weight of the DNA remained unchanged after ultraviolet irradiation and incubation at the restrictive temperature, despite the presence of the cdc9 mutation; these mutants are therefore incision defective. Low-molecular-weight DNA was observed in rad14 cdc9 and rad16 cdc9 strains. With the rad16 strain, the accumulation of low-molecular-weight DNA correlated with the amount of excision taking place, whereas in the rad14 mutant strain, no evidence of dimer removal was obtained. Therefore, rad14 is likely to be defective in a step after incision.

• Research Organization: Univ. of Rochester School of Medicine and Dentistry, NY
• DOE Contract Number: AC02-76EV03490
• OSTI ID: 5631968
• Journal Information: J. Bacteriol.; (United States), Journal Name: J. Bacteriol.; (United States) Vol. 148:2; ISSN JOBAA
• Country of Publication: United States
• Language: English

Related Subjects

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560400 -- Other Environmental Pollutant Effects
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BIOLOGICAL EFFECTS
BIOLOGY
DIMERS
DNA
ELECTROMAGNETIC RADIATION
FUNGI
GENETICS
MICROORGANISMS
MUTAGENESIS
MUTANTS
MUTATIONS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PLANTS
RADIATIONS
REMOVAL
SACCHAROMYCES
TEMPERATURE DEPENDENCE
ULTRAVIOLET RADIATION
YEASTS