Dimer excision in Escherichia coli in the presence of caffeine.

AUTOR(ES)

Rothman, R H

RESUMO

The observation that polA1 and recL152 mutations result in both slow pyrimidine dimer excision and large repair patch size leads to the hypothesis that patch size is directly related to the rate of excision. In this study caffeine, a known inhibitor of excision repair, was used to examine the extent of correlation between excision rate and patch size by measuring patch size in the presence of several concentrations of caffeine. Both the rate of excision and the resistance to ultraviolet radiation were reduced with increasing concentrations of caffeine after irradiation. Caffeine also inhibited the rate at which incisions were made and prolonged the time required to rejoin the discontinuities. Patch size, however, was unaffected by caffeine treatment.

Documentos Relacionados

• Stimulation of phiX174 production in mitomycin C-treated Escherichia coli cells by caffeine.
• Molecular mechanisms of DNA repair inhibition by caffeine.
• Pyrimidine dimer excision in surviving and nonsurviving cells of ultraviolet-irradiated cultures of Escherichia coli.
• Dimer excision and repair replication patch size in recL152 mutant of Escherichia coli K-12.
• Cytogenetic damage induced by folate deficiency in mice is enhanced by caffeine.