SUPPRESSION OF T4D LIGASE MUTATIONS BY rIIA AND rIIB MUTATIONS*
Abstract
The introduction of rII mutations into polynucleotide ligase amber mutants (gene 30) of T4D bacteriophage results in the restoration of phage growth in the nonpermissive host E. coli B. When cells are mixedly infected with rII+ -ligase- and rII-ligase- phage, growth is reduced, indicating that the rII mutations are recessive to the rII+ alleles. Infection with the rII-ligase- double mutants results in nearly complete restoration of phage DNA synthesis and prevents the extensive degradation of parental phage DNA observed after infection with ligase- single mutants. Similar results are observed when cells are infected with ligase- mutants and chloramphenicol is added five minutes post infection.
Footnotes
-
↵ † Department of Biology, The Johns Hopkins University, Baltimore, Maryland 21218.
-
↵ ‡ Department of Medical Genetics, The University of Pennsylvania, Philadelphia, Pennsylvania 19104.
-
↵ * This work was supported by National Institutes of Health grant AI 08161 (H. B.), National Science Foundation grant GB 13084 (A. K.) and National Institutes of Health grant CA 10055 (A. K.). The computer evaluation of data was performed in the University of Pennsylvania Medical School Computer Center, supported by National Institutes of Health grant FR 15-06.
