'plasmid'에 해당되는 글 1건
2007. 3. 29. 08:49
"Plasmid incompatibility" is well explained in this web-site of Genome Database of Naturally Occurring Plasmids managed by Department of Biochemistry and Molecular Biology, University College London.
Basically plasmids with same replication origin are thought to be incompatible. The most commonly used replication origins of E. coli vectors are pBR322-derived ColE1 and P15A replicons. Most of pET expression vectors contain ColE1 origin and pACYC derived plasmids contain P15A origin. However, several other origins can be used for multi plasmid experiments.
Recently, Novagen which developed the pET expression system launched DUET vectors. Each DUET vector has double T7 promoters and double multicloning sites. There are five vectors of DUET vectors with four diffferent origins.
The most famous but old review paper about plasmid incompatibility is "Plasmid Incompatibility, by RICHARD P. NOVICK (MICROBIOLOGICAL REVIEWS, Dec. 1987, p. 381-395)
But recently an interesting paper came out. The title is "Plasmid incompatibility: more compatible than previously thought?" The authors re-examined plasmid incompatibility concept in terms of the plasmid copy number, by introducing plasmids containing the same origin of replication and different antibiotic resistance genes into bacteria. And they showed that higher copy number leads to longer persistence, but even with low copy plasmids, persistence occurs to a significant degree.
Basically plasmids with same replication origin are thought to be incompatible. The most commonly used replication origins of E. coli vectors are pBR322-derived ColE1 and P15A replicons. Most of pET expression vectors contain ColE1 origin and pACYC derived plasmids contain P15A origin. However, several other origins can be used for multi plasmid experiments.
Recently, Novagen which developed the pET expression system launched DUET vectors. Each DUET vector has double T7 promoters and double multicloning sites. There are five vectors of DUET vectors with four diffferent origins.
- pACYCDuet-1 carries the P15A replicon, lacI gene and chloramphenicol resistance gene.
- pCDFDuet-1 carries the CloDF13 replicon, lacI gene and streptomycin/ spectinomycin resistance gene (aadA).
- pCOLADuet-1 carries the ColA replicon, lacI gene and kanamycin resistance gene.
- pETDuet-1 carries the pBR322-derived ColE1 replicon, lacI gene and ampicillin resistance gene.
- pRSFDuet-1 carries the RSF1030 replicon, lacI gene and kanamycin resistance gene.
The most famous but old review paper about plasmid incompatibility is "Plasmid Incompatibility, by RICHARD P. NOVICK (MICROBIOLOGICAL REVIEWS, Dec. 1987, p. 381-395)
But recently an interesting paper came out. The title is "Plasmid incompatibility: more compatible than previously thought?" The authors re-examined plasmid incompatibility concept in terms of the plasmid copy number, by introducing plasmids containing the same origin of replication and different antibiotic resistance genes into bacteria. And they showed that higher copy number leads to longer persistence, but even with low copy plasmids, persistence occurs to a significant degree.
