Summary: Treatment of growing with hydroxyurea decreased the DNA/protein ratio and markedly increased the specific activities of DNA polymerase and ATP-dependent deoxyribonuclease. These changes were similar to those produced by iron limitation of growth. Treating with nalidixic acid also decreased the DNA/protein ratio but had no effect on the activity of either enzyme. Growth of under conditions of zinc limitation did not diminish the specific activity of DNA polymerase thus not favouring a role for zinc in the action of this enzyme. The activity of the ATP-dependent deoxyribonuclease was, however, slightly increased. In previous reports the specific activity of DNA polymerase in this organism has been seriously underestimated due to interfering deoxyribonuclease and nucleoside triphosphatase. This was corrected by sufficient dilution of the extract. Revised specific activities of DNA polymerase in carbon-limited, nitrogen-limited and iron-limited cultures are, respectively, 10, 14, 11 and 64 units/mg protein.


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