Use of yeast transformation by oligonucleotides to study DNA lesion bypass in vivo.
Mutat Res
; 502(1-2): 53-60, 2002 May 22.
Article
em En
| MEDLINE
| ID: mdl-11996972
ABSTRACT
We have studied mutagenic specificities of DNA lesions in vivo in yeast CYC1 oligonucleotide transformation assay. We introduced two lesions into oligonucleotides. One was a nucleoside analog, 3,4-dihydro-6H,8H-pyrimido[4,5-c][1,2]oxazin-7-one 2'-deoxyriboside (dP), which is highly mutagenic to bacteria. It is supposed to be a miscoding, but otherwise good template for DNA polymerases. The other lesion was the TT pyrimidine(6-4)pyrimidone photoproduct, one of the typical UV lesions, which blocks DNA replication. These oligonucleotides were used to transform yeast cyc1 mutants with ochre nonsense mutation to Cyc1+. As expected from its templating properties in vitro, the transforming activity of dP-containing oligonucleotides was similar to those of unmodified oligonucleotides. Results indicated that dP may direct incorporation of guanine and adenine at a ratio of 120 or more in vivo. An oligonucleotide containing the photoproduct showed the transforming activity of as low as 3-5% of that of the corresponding unmodified oligonucleotide. This bypass absolutely required REV1 gene. The sequence analysis of the transformants has shown that the lesion was read as TT and TC at a ratio of 37, indicating its high mutagenic potential.
Buscar no Google
Base de dados:
MEDLINE
Assunto principal:
Oligonucleotídeos
/
Saccharomyces cerevisiae
/
Dano ao DNA
/
DNA Fúngico
/
Mutagênicos
Idioma:
En
Ano de publicação:
2002
Tipo de documento:
Article