Search results for "Plasmid preparation"

Dextransucrase Expression Is Concomitant with that of Replication and Maintenance Functions of the pMN1 Plasmid in Lactobacillus sakei MN1

2017

The exopolysaccharide synthesized by Lactobacillus sakei MN1 is a dextran with antiviral and immunomodulatory properties of potential utility in aquaculture. In this work we have investigated the genetic basis of dextran production by this bacterium. Southern blot hybridization experiments demonstrated the plasmidic location of the dsrLS gene, which encodes the dextransucrase involved in dextran synthesis. DNA sequencing of the 11,126 kbp plasmid (pMN1) revealed that it belongs to a family which replicates by the theta mechanism, whose prototype is pUCL287. The plasmid comprises the origin of replication, repA, repB, and dsrLS genes, as well as seven open reading frames of uncharacterized f…

Identification of SCP2165, a new SCP2-derived plasmid of Streptomyces coelicolor A3(2).

2005

Aims:  Characterization of SCP2165, a plasmid identified in the Gram-positive bacterium Streptomyces coelicolor A3(2). Methods and Results:  Pulsed-field gel electrophoresis (PFGE) of mycelia of a S. coelicolor strain embedded in low melting agarose revealed the presence of a plasmid. Restriction enzyme mapping and sequence analysis of a 2·1 kb fragment revealed that this plasmid could be SCP2. SCP2 and its spontaneous derivative SCP2* are self-transmissible plasmids and have chromosome mobilizing ability (c.m.a.). SCP2* has a c. 1000-fold increased c.m.a. compared with SCP2. Interestingly the plasmid, named SCP2165, shows a c.m.a. from 5 × 10−2 to 1 × 10−1 which is 50–100-fold higher than …

Isolation and purification of plasmids from Bacteroides fragilis using rubidium trichloroacetate density gradient centrifugation.

1983

A rapid and easy final purification method is described for the isolation of plasmids from B. fragilis. Using RbTCA density gradient centrifugation in an airfuge ultracentrifuge ccc plasmid DNA can be separated from RNA, residual chromosomal DNA, linear and oc plasmid DNA. Pure ccc plasmid DNA is obtained from cultures of between 1 ml and 2 l in less than one day.

Fast, non-toxic, and inexpensive n-butanol preparation of recombinant plasmids

2000

Various commercial and non-commercial plasmid preparation protocols are currently available. However, the kits are expensive and many of the protocols contain toxic chemicals. Here we present a novel, optimized and, therefore, very advantageous plasmid preparation protocol using n-butanol. The preparation can be performed quickly and no toxic chemicals are used, at overall costs of about one cent per plasmid preparation.Atualmente vários protocolos comerciais e não comerciais para preparação de plasmídeos estão disponíveis. Contudo, os kits são caros e muitos dos protocolos contêm substâncias químicas tóxicas. Apresentamos neste trabalho um novo, otimizado e portanto muito vantajoso protoco…

Correlation of plasmid DNA supercoiling and the efficiency of plasmid gene transcription

2007

UV-induced cross-linking of proteins to plasmid pBR322 containing 8-azidoadenine 2′-deoxyribonucleotides

1988

Abstract An efficient method of cross-linking DNA to protein is described. The method is based on the incorporation of photoactive 8-azidoadenine 2′-deoxyribonucleotides into DNA. We have found that 8-N 3 dATP is a substrate for E. coli DNA polymerase I and that 8-N 3 dATP can be incorporated into plasmid pBR322 by nick-translation. Subsequently we were able to cross-link a set of different proteins to 8-azido-2′-deoxyadenosine-containing pBR322 by UV irradiation (366 nm). No DNA-protein photocross-linking was observed under the same conditions when the non-photoactive plasmid pBR322 was used.