The presumed halothane metabolite, 2-bromo-1,1-difluoroethylene, produces both base substitution and frameshift mutations in Salmonella typhimurium. Direct mutagenesis of isolated DNA also was observed by using a Bacillus subtils transformation assay to score the production of mutagenic lesions in transforming DNA.

Engineered nucleases that cleave specific DNA sequences in vivo are valuable reagents for targeted mutagenesis. Here we report a new class of sequence-specific nucleases created by fusing transcription activator-like effectors (TALEs) to the catalytic domain of the FokI endonuclease. Both native and custom TALE-nuclease fusions direct DNA double-strand breaks to specific, targeted sites.

Footprinting and mutagenesis experiments demonstrated that Leptospira interrogans LexA binds the palindrome TTTGN(5)CAAA found in the recA promoter but not in the lexA promoter. In silico analysis revealed that none of the other canonical SOS genes is under direct control of LexA, making the leptospiral lexA gene the first described which is not autoregulated.

australian grapevine viroid (agvd), an apscaviroid of the family pospiviroidae, was recently identified in vineyards of southern iran. it had a relatively wide host range and caused stunting, leaf deformation, mottling and vein clearing in experimental hosts upon mechanical inoculation of nucleic acid extracts or agroinfiltration of the viroid infectious cloned dna. predicted secondary structur...

background: among all common techniques in sitedirectedmutagenesis, λ red recombinase system has beenwidely used to knock out chromosomal genes in bacteria. in thismethod, there is always the risk of dna linear digestion byhost's restriction enzymes that leads to the low frequency ofrecombination. objectives:to overcome this, we constructeda recombinant vector to disrupt phop gene in salmonella...

Genetic manipulation of Candida albicans is constrained by its diploid genome and asexual life cycle. Recessive mutations are not expressed when heterozygous and undesired mutations introduced in the course of random mutagenesis cannot be removed by genetic back-crossing. To circumvent these problems, we developed a genotypic screen that permitted identification of a heterozygous recessive muta...

Acridine-induced frameshift mutations in bacteriophage T4 occur at the precise location in the DNA at which acridines stimulate DNA cleavage by the T4-encoded type II topoisomerase in vitro. The mutations are duplications or deletions that begin precisely at the broken phosphodiester bond. In vivo, acridine-induced frameshift mutagenesis is reduced nearly to background levels when the topoisome...

BACKGROUND Targeted mutagenesis of the herpesvirus genomes has been facilitated by the use of bacterial artificial chromosome (BAC) technology. Such modified genomes have potential uses in understanding viral pathogenesis, gene identification and characterization, and the development of new viral vectors and vaccines. We have previously described the construction of a herpes simplex virus 2 (HS...

Two long-standing questions about glucansucrases (EC 2.4.1.5) are how they control oligosaccharide versus polysaccharide synthesis and how they direct their glycosidic linkage specificity. This information is required for the production of tailor-made saccharides. Mutagenesis promises to be an effective tool for enzyme engineering approaches for altering the regioselectivity and acceptor substr...