a self-regulated high-copy number plasmid containing chloramphenicol resistant gene, for the production of recombinant proteins under the regulation of bacteriophage ?pl promoter, was constructed. the designed 5024 base pair expression plasmid contained a heat sensitive repressor ci857 coding gene to regulate the function of ?pl promoter under heat shock induction. using the constructed vector,...

Previously, we described "promoter suppression" in infectious retrovirus vectors with two genes and an internal promoter. Here, we examined several parameters of promoter suppression and found that the amount of suppression in an integrated retrovirus vector was dependent both on whether the vector was derived from spleen necrosis virus or murine leukemia virus and on which internal promoter wa...

background: chitin is an abundant natural polysaccharide found in fungi, algae, and exoskeleton of insects. several bacterial species are capable of utilizing chitin as their carbon source. these bacteria produce chitinases for degradation of chitin into n-acetyl-d-glucosamine. so far, regulation of the chitinase encoding genes has been studied in different bacterial species. among bacillus spe...

BACKGROUND The human IGF2-P4 and IGF2-P3 promoters are highly active in a variety of human cancers, while existing at a nearly undetectable level in the surrounding normal tissue. Thus, a double promoter DTA-expressing vector was created, carrying on a single construct two separate genes expressing the diphtheria toxin a-fragment (DTA), from two different regulatory sequences, selected from the...

Fusion of two genes at DNA level produces a single protein, known as a chimeric protein. Immunotoxins are chimeric proteins composed of specific cell targeting and cell killing moieties. Bacterial or plant toxins are commonly used as the killing moieties of the chimeric immunotoxins. In this investigation, the catalytic domain of Shiga-like toxin (A1) was fused to human granulocyte macrophage ...

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...

fusion of two genes at dna level produces a single protein, known as a chimeric protein. immunotoxins are chimeric proteins composed of specific cell targeting and cell killing moieties. bacterial or plant toxins are commonly used as the killing moieties of the chimeric immunotoxins. in this investigation, the catalytic domain of shiga-like toxin (a1) was fused to human granulocyte macrophage c...

human interferon β (inf-β) is a member of cytokines family which different studies have shown its immunomodulatory and antiviral activities. in this study an expression vector was designed and constructed for expression of human inf-β-1b either in shake flasks and bench top bioreactor. the designed vector was constructed based upon pet-25b(+) with t7 promoter. recombinant human beta interferon ...

Knowing the nucleotide sequence of the cholera toxin operon, we designed oligonucleotide primers for its-PCR amplification from local clinical isolates of V. cholerae. The resulting amplification product was cloned in a common pUC18 vector. Subsequently, a part of this operon encoding the cholera toxin Bsubunit (CTB) was reamplified and cloned between the BamH1 and EcoR1 sites of the same ...

background: peroxisome proliferator activated receptor gamma (pparγ), a member of nuclear receptor superfamily, comprises two isoforms in mouse. these two isoforms are encoded by different mrnas, which are arisen by alternative promoter usage. there are two promoter regions upstream of pparγ gene. a 3 kb fragment, containing several transcription factor binding sites, acts as pparγ1 promoter re...