A novel mutagenesis technique using error-prone DNA polymerase δ (polδ), the disparity mutagenesis model of evolution, has been successfully employed to generate novel microorganism strains with desired traits. However, little else is known about the spectra of mutagenic effects caused by disparity mutagenesis. We evaluated and compared the performance of the polδMKII mutator, which expresses t...

Clavulanic acid is produced industrially by fermentation of Streptomyces clavuligerus and researches have increased its production by strain improvement, recombinant DNA technology, and media composition and growth condition optimization. The main objective of this study was to increase the level of clavulanic acid production from Streptomyces clavuligerus (DSM 738), using UV irradiation. After...

background: saccharomyces boulardii (s. boulardii) is the best known probiotic yeast. the genetic engineering of this probiotic strain requires the availability of appropriate mutants to accept various gene constructs carrying different selection markers. as the auxotrophy selection markers are under focus, we have generated a ura3 auxotroph mutant of s. boulardii for use in further genetic man...

A protocol combining recombination PCR and long-distance PCR is demonstrated to be highly accurate and rapid for site-directed mutagenesis of large (> 10 kb) plasmids. Application of this protocol to the generation of mutant rabies virus glycoproteins expressed by the baculovirus/insect cell system illustrates the usefulness of this approach in facilitating structure-function relationships in t...

1.Barany, F. 1985. Single-stranded hexameric linkers: a system for in-phase insertion mutagenesis and protein engineering. Gene 37:111-123. 2.Barany, F. 1985. Two-codon insertion mutagenesis of plasmid genes by using singlestranded hexameric oligonucleotides. Proc. Natl. Acad. Sci. USA 82:4202-4206. 3.Botstein, D. and D. Shortle. 1985. Strategies and applications of in vitro mutagenesis. Scienc...

The response regulator VirR and its cognate sensor histidine kinase, VirS, are responsible for toxin gene regulation in the human pathogen Clostridium perfringens. The C-terminal domain of VirR (VirRc) contains the functional FxRxHrS motif, which is involved in DNA binding and is conserved in many regulatory proteins. VirRc was cloned, purified, and shown by in vivo and in vitro studies to comp...

The thermostability of potato type L alpha-glucan phosphorylase (EC 2.4.1.1) was enhanced by random and site-directed mutagenesis. We obtained three single-residue mutations-Phe39-->Leu (F39L), Asn135-->Ser (N135S), and Thr706-->Ile (T706I)-by random mutagenesis. Although the wild-type enzyme was completely inactivated, these mutant enzymes retained their activity even after heat treatment at 6...