T7 phage induces two negative control mechanisms of protein synthesis: (a) Host-gene expression is repressed by a "T7 repressor," and (b) early T7 protein synthesis is inhibited by a late phage protein.(a) The repressor for host enzyme synthesis is an early T7 protein. Its gene is none of the known early genes; it is located promotor-proximal to gene 1. The repressor function of this protein ca...

T7 DNA polymerase with chemically inactivated 3'-5' exo-nuclease activity, as well as unmodified T7 DNA polymerase, were used for sequencing by the dideoxy method in an automated system with fluorescence labelled primer and on-line detection of laser-excited reaction products. An analysis of signal intensity variations in the C track revealed that low C signals were usually preceded by a T in t...

The T7 RNA polymerase-dependent transcription was studied as a function of nucleotide sequence structures positioned upstream of the T7 promoter. Model double-stranded DNA templates were constructed for this purpose. They contained a target sequence of 485 base pairs (cDNA fragment of Venesuelian encephalomyelitis equine virus genome), T7 promoter consensus and different extra base sequences up...

Chromatin immunoprecipitation combined with DNA microarrays (ChIP-chip) is a powerful technique to detect in vivo protein-DNA interactions. Due to low yields, ChIP assays of transcription factors generally require amplification of immunoprecipitated genomic DNA. Here, we present an adapted linear amplification method that involves two rounds of T7 RNA polymerase amplification (double-T7). Using...

The phage is used as a scaffold to display recombinant libraries of peptides, which provides the means to rescue and amplify peptides that bind target macromolecules. Many reports showed that the T7 phage display method can be used to obtain a ligand-binding peptidefor tissue-targeted therapies in adult animals. In utero tissue targeting of fetal tissues may help in the correction of many genet...

Angiogenesis is required for the invasion, metastasis and chemoresistance of tumor cells. In addition to vascular endothelial cell growth factor (VEGF), angiopoietin-2 (Ang2) is considered to be a promising target for anti-angiogenic therapy. The T7 peptide, an active fragment of full-length tumstatin [the noncollagenous 1 domain of the type IV collagen α3 chain, α3(IV)NC1], has equivalent anti...

The product of gene 2.5 of bacteriophage T7, a single-stranded DNA binding protein, physically interacts with the phage-encoded gene S protein (DNA polymerase) and gene 4 proteins (helicase and primase) and stimulates their activities. Genetic analysis ofT7 phage defective in gene 2.5 shows that the gene 2.5 protein is essential for T7 DNA replication and growth. T7 phages that contain null mut...

Inability of T7 RNA polymerase to processively transcribe higher eukaryotic chromatin is interpreted as a correlate of its reported inhibition by nucleosomes on reconstituted templates in vitro . We used chromosomally integrated reporter cassettes to examine features of T7 transcription in a lower eukaryotic system. Luciferase reporters were targeted to rDNA in transgenic Trypanosoma brucei sta...

Overexpression of udk, an Escherichia coli gene encoding a uridine/cytidine kinase, interferes with T7 bacteriophage growth. We show here that inhibition of T7 phage growth by udk overexpression can be overcome by inhibition of host RNA polymerase. Overexpression of gene 2, whose product inhibits host RNA polymerase, restores T7 phage growth on hosts overexpressing udk. In addition, rifampicin,...

Background:In the recent decade, the reverse genetics method has been broadly used for rescue of negative-stranded RNA viruses from cDNA or viral minigenomes. This technique has been applied to study different steps in virus replication and virus-host interactions. Reverse genetics could also be implemented for design of new vaccines. The T7 RNA polymerase activity as well as virus (nucleocapsi...