The DNA polymerases (gp43s) of the two related phages T4 and RB69 are DNA-binding proteins that also function as mRNA-binding autogenous translational repressors. As repressors, T4 gp43 is narrowly specific to its own mRNA whereas RB69 gp43 is equally effective against mRNA for either protein. We used in vitro RNase-sensitivity and RNA footprinting assays to identify features of the non-identic...

Thyroid hormones (TH) have been shown to exert a direct stimulatory effect on the Ca++-dependent ATPase from human and other mammalian erythrocytes. In this in vitro system, T4 has been shown to be more effective than T3. In the present study, TH effects on Ca++-dependent ATPase were investigated, using rabbit and human erythrocyte membranes, after preincubation with 10(-10) M T4, in the presen...

Objective: The primary aim of this study was the early detection and treatment of hypothyroidism in neonates. This paper describes the determination of cord blood serum T4 and TSH levels, their mean levels, reference ranges and interrelationship. Design: Retrospective analysis of serum T4 and TSH levels in 1153 cord blood samples collected and analyzed during July 1998 to June 2000. Setting: Ce...

The mutagenic action of proflavin on bacteriophage T4 is greater in the presence of defective T4 ligase than in the presence of normal T4 ligase. This suggests that the persistence of single-strand breaks in DNA enhances proflavin mutagenesis.

The RNA polymerase from bacteriophage T4-infected Escherichia coli, which specifically initiates transcription at phage T4 late promoters, is extensively modified by ADP-ribosylation of core subunits and by binding several virus-encoded subunits. We show here that one of these subunits, the phage T4 gene 55 protein, designated gp55, alone endows unmodified RNA polymerase core enzyme from uninfe...

By recombination between bacteriophage T4 wh2, a dihydrofolate reductaseless mutant, and T6, I have prepared T4 wh(T6), a T4 strain which codes for the T6-specific soluble dihydrofolate reductase. This strain has the heat sensitivity of T6, not T4, which provides direct evidence that the wh gene codes for both the soluble dihydrofolate reductase and the structural dihydrofolate reductase which ...

Phage T4 amber mutants defective in gene 42 (dCMP hydroxymethylase) were shown by in vivo and in vitro experiments to participate in both positive and negative intragenic complementation. This argues that incomplete polypeptide chains can participate in subunit interaction.

As previously shown, a small amount of polynucleotide material is added to parental T4 deoxyribonucleic acid (DNA) molecules within the first 5 min of infection. I have asked whether this process is essential for phage replication. Two approaches-one involving decay of (32)P incorporated into this "early DNA" and the other involving photoinactivation of bromodeoxyuridine-containing early DNA-in...

Complexes of substructural elements of bacteriophage T4 (baseplates, baseplate-core complexes) with long tail fibres were obtained for the first time by complementation in vitro. A study of the organization of the complexes was carried out by PAGE, electron microscopy and sedimentation analysis. About 90% of baseplates and baseplate-core complexes were combined with fibres. However, the number ...

Endonuclease VII is a Holliday-structure resolving enzyme of phage T4 which cleaves at junctions of branched DNAs and at mispairings. In extension of these findings we report the following: i) Endonuclease VII can discriminate between a large heteroduplex loop and a TT mismatch arranged in tandem, 6 nt distant from each other, in the same heteroduplex molecule. The enzyme cleaves two nucleotide...