期刊
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
卷 98, 期 12, 页码 6901-6904出版社
NATL ACAD SCIENCES
DOI: 10.1073/pnas.121171698
关键词
Pseudomonas aeruginosa; twitching motility; fluorescence
Type IV pill are thin filaments that extend from the poles of a diverse group of bacteria, enabling them to move at speeds of a few tenths of a micrometer per second. They are required for twitching motility. e,g,, in Pseudomonas aeruginosa and Neisseria gonorrhoeae, and for social gliding motility in Myxococcos xanthus, Here we report direct observation of extension and retraction of type IV pill in P. aeruginosa, Cells without flagellar filaments were labeled with an amino-specific Cy3 fluorescent dye and were visualized on a quartz slide by total internal reflection microscopy. When pill were attached to a cell and their distal ends were free, they extended or retracted at rates of about 0.5 mum s(-1) (29 degreesC). They also flexed by Brownian motion, exhibiting a persistence length of about 5 mum. Frequently, the distal tip of a filament adsorbed to the substratum and the filament was pulled taut. From the absence of lateral deflections of such filaments, we estimate tensions of at least 10 pN. Occasionally, cell bodies came free and were pulled forward by pilus retraction. Thus, type IV pill are linear actuators that extend, attach at their distal tips, exert substantial force, and retract.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据