Work

Single pilus motor forces exceed 100 pN

Year: 2002

Type: article

Abstract: 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.

Source: Proceedings of the National Academy of Sciences

DOI: 10.1073/pnas.242523299

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

Institutions: Oregon Health & Science University, Columbia University

Language: English

Topic: Biochemical and Structural Characterization

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: green

Funder: National Institute of Allergy and Infectious Diseases

Award: Formation of Cortical Plaques by Neisseria