- The 2µ plasmid, also called 2-µm plasmid, is a naturally occurring, circular DNA molecule found in Saccharomyces cerevisiae (budding yeast).
- It is relatively small, measuring around 6.3 kilobases, and exists in high copy numbers within the yeast nucleus, typically ranging from 40 to 60 copies per cell.
- This plasmid is considered a selfish genetic element because its primary purpose is self-maintenance and propagation, providing no significant advantage to the host organism.
- Key features of the 2µ plasmid include its origin of replication (ORI), which allows independent replication, and the STB locus, responsible for stable segregation during cell division.
- It also relies on Flp recombinase-mediated site-specific recombination to regulate its copy number through Flp Recognition Targets (FRTs).
- Additionally, the plasmid encodes proteins like Rep1, Rep2, Raf1, and Flp, which are essential for replication, stability, and recombination processes.
- While the 2µ plasmid has no direct impact on yeast fitness, its stability and high copy number have made it a valuable tool in biotechnology, particularly for gene cloning and expression systems.
