Single pilus motor forces exceed 100 pN

Berenike Maier, Laura Potter, Magdalene So, Hank S. Seifert, Michael P. Sheetz

Research output: Contribution to journalArticlepeer-review

276 Scopus citations


Force production by type IV pilus retraction is critical for infectivity of Neisseria gonorrhoeae and DNA transfer. We investigated the roles of pilus number and the retraction motor, PilT, in force generation in vivo at the single-molecule level and found that individual retraction events are generated by a single pilus fiber, and only one PilT complex powers retraction. Retraction velocity is constant at low forces but decreases at forces greater than 40 pN, giving a remarkably high average stall force of 110 ± 30 pN. Further insights into the molecular mechanism of force generation are gained from the effect of ATP-depletion, which reduces the rate of retraction but not the stall force. Energetic considerations suggest that more than one ATP is involved in the removal of a single pilin subunit from a pilus. The results are most consistent with a model in which the ATPase PilT forms an oligomer that disassembles the pilus by a cooperative conformational change.

Original languageEnglish (US)
Pages (from-to)16012-16017
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number25
StatePublished - Dec 10 2002
Externally publishedYes

ASJC Scopus subject areas

  • General


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