The R1 plasmid is a plasmid that was first isolated from Salmonella paratyphi bacteria in 1963.[1] It is a short plasmid, composed of 97,566 nucleotides and 120 genes, that belongs to the IncFII plasmid group.[2]
The R1 plasmid imparts multi-drug antibiotic resistance to its host bacteria.[3]
It's known as a "low copy" plasmid, meaning that it exists in relatively few copies in any given bacteria. This characteristic allows the R1 plasmid to have an efficient plasmid stabilization system, that aids in stabilizing medium copy number plasmids.[4][page needed] R1 must rely on a "Type II" segregation system. This plasmid system ensures that at least one copy is contained in each daughter cell after cell division.[3]