Abstract In this study, we constructed recombinant luminescent Escherichia coli with T7, T3, and SP6 promoters inserted between tol lux genes as toluene biosensors evaluated their sensitivity, selectivity, specificity for measuring bioavailable in groundwater river water. The luminescence intensity of each biosensor depended on temperature, incubation time, ionic strength, concentrations coexis...

We have discovered that T7 RNA polymerase, purified to apparent homogeneity from overexpressing Escherichia coli cells, possesses a DNase and an RNase activity. Mutations in the active center of T7 RNA polymerase abolished or greatly decreased the nuclease activity. This nuclease activity is specific for single-stranded DNA and RNA oligonucleotides and does not manifest on double-stranded DNAs....

The gene encoding bacteriophage T7 RNA polymerase (T7gene1) was placed under the control of regulatory elements from the Escherichia coli lac operon to construct an inducible vaccinia virus expression system consisting entirely of prokaryotic transcriptional machinery. Regulated expression of T7 RNA polymerase was necessary to construct a stable recombinant vaccinia virus harboring a T7 promote...

Background and Aims: Q59L mutant of L-asparaginase enzyme from Escherichia coli (E. coli) has been introduced with lower side effects. This version of the enzyme might have potential applications in the treatment of leukemia patients. We utilized SHuffle T7 strain of E. coli, to produce the mutant enzyme in the presence of chaperone molecules. Materials and Methods: Q59LAsp gene was cloned in...

BACKGROUND Amino acid sequence diversity is introduced into a phage-displayed peptide library by randomizing library oligonucleotide DNA. We recently evaluated the diversity of peptide libraries displayed on T7 lytic phage and M13 filamentous phage and showed that T7 phage can display a more diverse amino acid sequence repertoire due to differing processes of viral morphogenesis. METHODS In t...

Single-stranded DNA-binding protein (gp2.5), encoded by gene 2.5 of bacteriophage T7, plays an essential role in DNA replication. Not only does it remove impediments of secondary structure in the DNA, it also modulates the activities of the other replication proteins. The acidic C-terminal tail of gp2.5, bearing a C-terminal phenylalanine, physically and functionally interacts with the helicase...

A continuum computation is proposed for the bending stress stabilizing DNA that is hexagonally packed within bacteriophage T7. Because the inner radius of the DNA spool is rather small, the stress of the curved DNA genome is strong enough to balance its electrostatic self-repulsion so as to form a stable hexagonal phase. The theory is in accord with the microscopically determined structure of b...

The lactococcal abortive infection mechanisms AbiA and AbiG were introduced into Streptococcus thermophilus 4035, and a range of phages capable of infecting this host were examined for sensitivity to these mechanisms. AbiA proved effective against six phages when examined at a growth temperature of 30 degrees C but had no effect on any of the phages when tested at 37 or 42 degrees C. AbiG faile...