Transcriptional Control of T4 Coliphage-Specific Genes 30, 42, 43, rIIA, rIIB, and e

Abstract

SUMMARYEscherichia coli B[r (su °) was infected, at 30 °C, with T4Dam +, , and T4DamNx34amBL292 (33-, 55-, maturation-defective phenotype). A genetic (' transformation') assay was used to monitor transcription of genes 30 (polynucleotide ligase), 42 (deoxycytidylate hydroxymethylase), 43 (DNA polymerase), rlIA, rlIB, and e (endolysin). The principal results are: (t) All of the genes studied were transcribed exclusively from the so-called/-strand of phage DNA. (2) DNA synthesis and the maturation-defective proteins were required to turn-off transcription of genes 42, rIIA, tIIB, and 43.

Kinetics and thermodynamics of nick sealing by T4 DNA ligase

“…In vitro pre‐steady‐state kinetic studies performed in this work suggest that T4 DNA ligase could rapidly adenylate mismatching nicks in the infected cells, either at the late stages of degradation of the cellular DNA or during the subsequent replication of the coliphage T4 DNA: the ligase gene is transcribed at steady levels throughout the eclipse, reaching its maximum 3 min after infection [32]. The sealing of these pre‐adenylated nicks, however, would be slow because of relatively high intracellular [ATP] (1–3 m m ) [33].…”

Deoxythymidine nucleotide metabolism in Bacillus subtilis W23 infected with bacteriophage SP1Oc: preliminary evidence that dTMP in SP10c DNA is synthesized by a novel, bacteriophage-specific mechanism

“…The DNAs were denatured by dialysis against distilled water followed by heating at 600C for 5 min. The denatured DNAs were hydrolyzed to mononucleotides by treatment with Si nuclease of Aspergillus oryzae (1,27,34) and snake venom phosphodiesterase (31). Commercially available snake venom phosphodiesterase was purified further to remove residual phosphatase and 5'-nucleotidase activity (23).…”