Mobilization of Bacillus thuringiensis plasmid pTX14-3.
The Bacillus thuringiensis subsp. israelensis (Bti) plasmid pTX14-3 has been reported to contain a gene, mob14-3, with considerable homology to genes encoding mobilization proteins from other gram-positive bacteria. We have used the aggregation-mediated conjugation system recently discovered in Bti to compare the mobilization kinetics of different derivatives of plasmid pTX14-3. Plasmid pTX14-3 has been found to replicate by the rolling-circle mechanism and to contain a locus suppressing the formation of high-molecular-weight DNA. We found that deleting a DNA fragment containing this locus increased the transfer frequency about twofold. The mobilization frequency of the plasmid containing the intact mob14-3 gene did not indicate a mobilization-enhancing activity of the encoded polypeptide. However, the presence of the mob14-3 gene seemed to increase the stability of the plasmid in exponential growth.
Andrup
L
L
National Institute of Occupational Health, Department of Toxicology and Biology, Copenhagen, Denmark.
Bendixen
H H
HH
Jensen
G B
GB
D001413:Bacillus thuringiensis / Q000235:genetics*; D003001:Cloning, Molecular; D003227:Conjugation, Genetic; D003433:Crosses, Genetic; D004269:DNA, Bacterial / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli; D005798:Genes, Bacterial; D006094:Gram-Positive Bacteria / Q000235:genetics; D010957:Plasmids; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
D004269:DNA, Bacterial