DNA transport into Bacillus subtilis requires proton motive force to generate large molecular forces.

TitleDNA transport into Bacillus subtilis requires proton motive force to generate large molecular forces.
Publication TypeJournal Article
Year of Publication2004
AuthorsMaier, B, Chen, I, Dubnau, D, Sheetz, MP
JournalNat Struct Mol Biol
Volume11
Issue7
Pagination643-9
Date Published2004 Jul
ISSN1545-9993
KeywordsBacillus subtilis, Biological Transport, DNA, Protons
Abstract

Bacteria can acquire genetic diversity, including antibiotic resistance and virulence traits, by horizontal gene transfer. In particular, many bacteria are naturally competent for uptake of naked DNA from the environment in a process called transformation. Here, we used optical tweezers to demonstrate that the DNA transport machinery in Bacillus subtilis is a force-generating motor. Single DNA molecules were processively transported in a linear fashion without observable pausing events. Uncouplers inhibited DNA uptake immediately, suggesting that the transmembrane proton motive force is needed for DNA translocation. We found an uptake rate of 80 +/- 10 bp s(-1) that was force-independent at external forces <40 pN, indicating that a powerful molecular machine supports DNA transport.

DOI10.1038/nsmb783
Alternate JournalNat. Struct. Mol. Biol.