Synthesis of DNA containing uracil during bacteriophage infection of Bacillus subtilis. Technical progress report, August 1, 1975--July 31, 1976

Abstract

We have studied the synthesis of proteins and nucleic acids to understand how the bacteriophage PBS2 can make uracil-containing DNA in a cell which normally makes thymine-containing Bacillus subtilis DNA. We showed that the earliest known PBS2-induction of a protein is the inhibitor of the B. subtilis N-glycosidase (or uracil-DNA nuclease). This enzyme cleaves uracil from PBS2 DNA, and it is inhibited before any other known PBS2 protein appears in infected cells. The PBS2 dUMP kinase, which probably provides dUTP for uracil-DNA synthesis, has been partially characterized. Purification and induction in polymerase I- and III-deficient host cells indicate that the PBS2 DNA polymerase is a new enzyme. However, infection of temperature-sensitive polymerase III mutants suggests that the host's DNA polymerase III may play some role in PBS2 replication, at least under certain conditions. Two-dimensional thin-layer chromatography methods have been developed to quantitate the deoxyribonucleoside triphosphate pools before and after PBS2 infection.