English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Requirements for bacteriophage T4 DNA synthesis have been investigated in situ by use of plasmolyzed infected cells. When such cells are incubated with dATP, dGTP, dTTP, hydroxymethyldeoxycytidine triphosphate, and rATP, significant semiconservative synthesis of DNA occurs. This DNA hybridizes preferentially to T4 DNA. T4 amber mutants defective in genes 44 and 45, which display a DNA-negative phenotype in vivo, are unable to synthesize DNA in situ. By contrast, T4 amber mutants bearing lesions in genes 41 and 62, which also display a DNA-negative phenotype in vivo, do allow DNA synthesis in situ, the extent of synthesis being 80 to 90% that of the wild-type synthesis under the same conditions. Cells infected with gene 42 mutants (dCMP hydroxymethylase) are unable to synthesize DNA in situ even though exogenous nucleotides are provided. Also one gene 1 mutant (deoxynucleotide kinase) was found to synthesize DNA in situ, but two other gene 1 mutants did not. These results point to possible roles of hydroxymethylase and kinase in DNA metabolism, in addition to provision of essential DNA precursors, as has recently been suggested by Wovcha et al. (1973).

Biochemistry of DNA-Defective Amber Mutants of Bacteriophage T4 IV. DNA Synthesis in Plasmolyzed Cells