Plasmid transformation in Bacillus subtilis: factors affecting the synapsis of donor and recipient DNA.

Hybrid plasmids were constructed in which the transcription of regions of inserted DNA was defined. Cells containing these plasmids were transformed with monomeric forms of a different hybrid plasmid, which contained, however, the same inserted DNA as the resident plasmid. The transformation frequencies observed indicated that transcription of homologous DNA in resident plasmids and also tertiary DNA structure interfered with transformation.