Characterization of plasmid pASV479 from Bifidobacterium pseudolongum subsp. globosum and its use for expression vector construction.

Bifidobacterium pseudolongum subsp. globosum DPC479 is an intestinally-derived strain which contains a plasmid, pASV479, 4.8 kb in size. This plasmid has a G + C content of 59% and contains six open reading frames (ORFs), four of which are cryptic. The other two ORFs have 47% and 54% identity, respectively, to the replication and FtsK-like proteins found in a Bifidobacterium breve NCFB 2258 plasmid, indicating that these plasmids, though isolated from differing Bifidobacterium species, are related. Using this plasmid as a backbone, an expression vector, pBIFRIBO, was constructed which exploits a bifidobacteria rRNA promoter.