Fig.1 Map of the conjugative plasmid pSVH1 from the chloramphenicol producer Streptomyces venezuelae.
Functions involved in replication (black), regulation (red), transfer (blue) and intramycelial plasmid spreading (yellow) are indicated.
Fig. 2 Pock structures formed during conjugative transfer of plasmid pSVH1.
S. lividans TK23 carrying the pSVH1 derivative pEB211 was streaked on a lawn of plasmid free S. lividans TK64.
Fig. 3 Vizualization of conjugative transfer and plasmid spreading within recipient hyphae.
Spores of the donor S. lividans TK23 (pLT303) (green) and the recipient S. lividans T7–mCherry (red) were mixed and plated. After 20 h of growth at 29°C cells were imaged by fluorescence microscopy. Transconjugant hyphae appear yellow in the overlay. Scale bar, 5 µm.
Fig. 4 Structure and pore forming ability of TraBpSVH1.
Electron microscopy of TraB shows a ring-shaped morphology. 2D averaging of electron microscopic images and homology modelling (template DNA-translocase domain of P. aeruginosa FtsK) of soluble TraB lacking the N-terminal membrane domain show a hexameric structure with a ~ 12 nm central channel. Single channel recordings in planar lipid bilayers revealed a pore forming ability of TraB.
Fig. 5 Bifunctional Streptomyces vectors. Plasmids are based on the minimal replicon of pSG5.