Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Bacteriol. 2009 Jul;191(14):4633-8. doi: 10.1128/JB.00396-09. Epub 2009 May 8.

High-force generation is a conserved property of type IV pilus systems.

Author information

  • 1Department for Biology, Westfälische Wilhelms Universität, Münster, Germany.

Abstract

The type IV pilus (T4P) system of Neisseria gonorrhoeae is the strongest linear molecular motor reported to date, but it is unclear whether high-force generation is conserved between bacterial species. Using laser tweezers, we found that the average stalling force of single-pilus retraction in Myxococcus xanthus of 149 +/- 14 pN exceeds the force generated by N. gonorrhoeae. Retraction velocities including a bimodal distribution were similar between M. xanthus and N. gonorrhoeae, but force-dependent directional switching was not. Force generation by pilus retraction is energized by the ATPase PilT. Surprisingly, an M. xanthus mutant lacking PilT apparently still retracted T4P, although at a reduced frequency. The retraction velocity was comparable to the high-velocity mode in the wild type at low forces but decreased drastically when the force increased, with an average stalling force of 70 +/- 10 pN. Thus, M. xanthus harbors at least two different retraction motors. Our results demonstrate that the major physical properties are conserved between bacteria that are phylogenetically distant and pursue very different lifestyles.

PMID:
19429611
[PubMed - indexed for MEDLINE]
PMCID:
PMC2704717
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk