SUMMARY: Addition of cytidine or guanosine to UV-irradiated cells of a RecAstrain of did not produce any effect on the induction of two SOS functions: inhibition of cell division and expression of the gene. Under the same conditions adenine gave a slight increase in the induction of these two responses. In a RecA441 mutant growing at 42°C, both cytidine and guanosine inhibited these SOS functions, whereas adenine produced a large increase in their expression. Moreover, the ATP concentration of the RecA441 mutant at 42°C showed a decrease which occurred earlier in the cells growing in the presence of cytidine or guanosine than in the absence of either compound. Adenine induced an increase of about three times the initial ATP concentration of this mutant at 42°C which dropped quickly after 10 min. Neither cytidine nor guanosine increased the evolution of cellular ATP in UV-irradiated cells of the RecAstrain, whereas adenine had only a slight positive effect. However, in UV-irradiated RecAcells with and without adenine, ATP levels dropped quickly to the initial value after 20 min. These data suggest that the influence of adenine, cytidine and guanosine on the expression of the RecA441 phenotype at 42°C may be due to alteration of the cellular ATP concentration of this mutant.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error