Agrobacterium tumefaciens harboring a Ti plasmid causes plant tumorigenesis and it's DNA transfer system have been extensively used in plant biotechnology. Because Ti plasmids are high stable in agrobacterial hosts, their curing is very difficult by conventional methods. Here, we introduced a novel curing method by using Ti plasmids incompatibility.

The conjugational transfer efficiency of 41 wild-type R-plasmids was studied in Escherichia coli K-12. Type I R-plasmids were transferred at comparatively high and rather uniform frequencies, whereas type F R-plasmids showed less uniform and, on average, somewhat lower transfer frequencies. R-plasmids not mediating sensitivity to F-, I-, or N-specific phages showed moderate transfer frequencies...

Abstract Background Metagenomic sequencing has led to the identification and assembly of many new bacterial genome sequences. These bacteria often contain plasmids: usually small, circular double-stranded DNA molecules that may transfer across species confer antibiotic resistance. plasmids are generally less studied understood than their hosts. Part reason for this is insufficient computational...

Abstract Background The presence of antibiotic resistant microorganisms in food is great concern globally. This research was carried out to detect and characterize plasmid carriage profiles among members Enterobacteriaceae from different meat types Nigeria. Method From a total 80 samples comprising mutton, pork, beef chicken, organisms belonging the family were isolated by standard procedures i...

Plasmids play important roles in horizontal gene transfer among Vibrionaceae, but surprisingly little is known about their replication and incompatibility systems. In this study, we successfully developed a bioinformatics-assisted strategy of experimental identification of 7 Vibrio plasmid replicons. Comparative sequences analysis of the 7 Vibrio plasmid replicons obtained in this study togethe...

We have surveyed naturally occurring plasmids in strains of Bacillus subtilis and the closely related species B. mojavensis and B. licheniformis. Previous studies have failed to find host-benefitting functions for plasmids of these species, suggesting that these plasmids are nonmutualistic. Only one type of plasmid was found in each plasmid-bearing strain, suggesting that most of the plasmids i...

Twelve strains of Agrobacterium radiobacter isolated from naturally occurring crown galls or soil were found to be avirulent on sunflower, tomato, Kalanchoe, and carrot. Eleven strains contained plasmids of molecular weights 77 X 10(6) to 182 X 10(6) as determined by electron microscopy. One strain contained only a smaller plasmid (50 X 10(6) daltons). Several strains had both large and small (...

background: protozoa related to trypanosome family including leishmania , synthesize enzymes to escape from drug therapy. one of them is ptr1 that its enzymatic activity is similar to dihydrofolate reductase (dhfr). dihydrofolate reductase - thymidylate synthase has a major role in dna synthesis, if it is inhibited, the result would be the death of parasite. since ptr1 activity is similar to dh...

objective(s): adeno-associated virus type 2 (aav2) vectors are widely used for both experimental and clinical gene therapy. a recent research has shown that the performance of these vectors can be greatly improved by substitution of specific surface-exposed tyrosine residues with phenylalanines. in this study, a fast and simple method is presented to generate aav2 vector helper plasmids encodin...