The effect of high electric fields on the gel-electrophoretic mobility of open-circular DNA in agarose differs dramatically from that on linear molecules of the same molecular weight. At high fields, sufficiently large circular forms are prevented from migrating into the gel whereas linear molecules and smaller circular DNAs migrate normally. This effect is strongly field dependent, affecting c...

Plasmid pSLL of Streptomyces laurentii ATCC31255 (wild-type strain P0) is a 93-kilobase linear DNA plasmid that carries a protein bound to each 5' end of the DNA. It was self-transmitted to the pSLL-cured strain by conjugation in solid culture. The pSLL-cured strain carried a circular plasmid, pSLS, and showed a marked decrease in spore formation and thiostrepton productivity, owing to the pSLS...

Borrelia miyamotoi, of the relapsing-fever spirochete group, is an emerging tick-borne pathogen causing human illness in the northern hemisphere. Here, we present the chromosome, eight extrachromosomal linear plasmids, and a draft sequence for five circular and one linear plasmid of a Borrelia miyamotoi strain isolated from an Ixodes sp. tick from Connecticut, USA.

Conventional plasmid DNA vectors play a significant role in gene therapy, but they also have considerable limitations: they can elicit adverse immune responses because of bacterial sequences they contain for maintenance and amplification in prokaryotes, their bioavailability is compromised because of their large molecular size, and they may be genotoxic. We constructed an in vivo platform to pr...

The presence of restriction enzymes in the transformation mixture improved the efficiency of transformation in Moniliophthora perniciosa. The influence of the vector shape (linear or circular), the patterns of plasmid integration in genomic sites and the influence of the promoter used to express the gene marker were also analyzed. The addition of BamHI or NotI increased the number of transforma...

Pulsed-field gel electrophoresis (PFGE) was used to examine the in vivo and in vitro conformations of Physarum polycephalum mitochondrial DNA (mtDNA). We used plugs containing isolated mitochondria, isolated mitochondrial nucleoids (mt-nuclei), and isolated mtDNA, in addition to whole cells. The mtDNA contained in the myxamoebae, plasmodia, isolated mitochondria, and isolated mt-nuclei was circ...

Polymerase chain reaction (PCR) is a powerful method to produce linear DNA fragments. Here we describe the Tma thermostable DNA ligase-mediated PCR production of circular plasmid (PPCP) and its application in directed evolution via in situ error-prone PCR. In this thermostable DNA ligase-mediated whole-plasmid amplification method, the resultant DNA nick between the 5' end of the PCR primer and...

The majority of the human population harbors latent cytomegalovirus. Although CD14(+) peripheral blood mononuclear cells have been implicated as sites of latency, the conformation of the latent viral genome in these cells is unknown. In this study, the conformation of viral genomic DNA was assessed in CD14(+) cells from healthy virus seropositive carriers using an electrophoretic separation on ...