Inhibition of thymidylate synthetase in bacteriophage-infected Bacillus subtilis

The Inactivation of Microbial Enzymes in Vivo

“…Many casual reports of the loss of enzyme activity from microbial cells exist, but I have attempted to concentrate on those cases in which the inactivation process itself was a focus of attention. Cases of the inactivation of enzymes in phage-infected bacteria (29,47,81,99,109,131) and in differentiating slime molds (2,43,64,125) have not been included because of space limitations and because of their specialized nature. Table 1 lists 41 examples of reasonably well-characterized inactivation processes occurring in microbes that were found in a survey of the literature from about 1945 to mid 1976.…”

Bacteriophages of Bacillus subtilis.

“…Two types of phage-directed proteins were thought to contribute to this depletion, an inhibitor of thymidylate synthetase (119), and hydrolases capable of degrading dTIP (257). This idea has been abandoned because suppression of host DNA replication occurs in cells infected with dTTPase-less phage mutants (258).…”

Bacillus subtilis DNA Polymerase III Is Required for the Replication of the Virulent Bacteriophage φe

“…We were interested in understanding the mechanism whereby qe arrests host DNA synthesis several minutes after infection (16,18,24,25). This phage induces on infection the synthesis of both an inhibitor of the host thymidylate synthetase and a deoxythymidinetriphosphate nucleotidohydrolase (dTTPase) (13,24,25). Previous studies have shown that depletion of the dTTP pool in 4e-infected cells is not the only cause for host-DNA arrest by this phage.…”

“…This phage belongs to a group of large, double-stranded DNA phages of Bacillus subtilis (1, 11, 14, 21,26). The lytic cycle of-be has been characterized (13,(24)(25)(26). Roscoe (25) found that host DNA synthesis is arrested in (e-infected cells several minutes after infection and phage DNA synthesis begins.…”