Transformation proteins and DNA uptake localize to the cell poles in Bacillus subtilis.
The Gram-positive, rod-forming bacterium Bacillus subtilis efficiently binds and internalizes transforming DNA. The localization of several competence proteins, required for DNA uptake, has been studied using fluorescence microscopy. At least three proteins (ComGA, ComFA, and YwpH) are preferentially associated with the cell poles and appear to colocalize. This association is dynamic; the proteins accumulate at the poles as transformability develops and then delocalize as transformability wanes. DNA binding and uptake also occur preferentially at the cell poles, as shown using fluorescent DNA and in single-molecule experiments with laser tweezers. In addition to the prominent polar sites, the competence proteins also localize as foci in association with the lateral cell membrane, but this distribution does not exhibit the same temporal changes as the polar accumulation. The results suggest the regulated assembly and disassembly of a DNA-uptake machine at the cell poles.
Hahn
Jeanette
J
Public Health Research Institute, 225 Warren Street, Newark, New Jersey 07103, USA.
Maier
Berenike
B
Haijema
Bert Jan
BJ
Sheetz
Michael
M
Dubnau
David
D
D001412:Bacillus subtilis / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000502:physiology*; D016764:Cell Polarity / Q000502:physiology*; D004269:DNA, Bacterial / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D013997:Time Factors; D014169:Transformation, Bacterial
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C083532:comF1 protein, Bacillus subtilis