Journal
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Volume 111, Issue 13, Pages 4880-4885Publisher
NATL ACAD SCIENCES
DOI: 10.1073/pnas.1401025111
Keywords
bacterial chromosome segregation; ParA ATPase; spatial organization; protein gradients
Categories
Funding
- National Institute of Diabetes and Digestive and Kidney Diseases
- National Heart, Lung, and Blood Institute
- National Institutes of Health US Department of Health and Human Services
- Nancy Nossal Fellowship
Ask authors/readers for more resources
The faithful segregation of duplicated genetic material into daughter cells is critical to all organisms. In many bacteria, the segregation of chromosomes involves transport of centromere-like loci over the main body of the chromosome, the nucleoid, mediated by a two-protein partition system: a nonspecific DNA-binding ATPase, ParA, and an ATPase stimulator, ParB, which binds to the centromere-like loci. These systems have previously been proposed to function through a filament-based mechanism, analogous to actin-or microtubule-based movement. Here, we reconstituted the F-plasmid partition system using a DNA-carpeted flow cell as an artificial nucleoid surface and magnetic beads coated with plasmid partition complexes as surface-confined cargo. This minimal system recapitulated directed cargo motion driven by a surface ATPase gradient that propagated with the cargo. The dynamics are consistent with a diffusion-ratchet model, whereby the cargo dynamically establishes, and interacts with, a concentration gradient of the ATPase. A chemophoresis force ensues as the cargo perpetually chases the ATPase gradient, allowing the cargo to essentially surf the nucleoid on a continuously traveling wave of the ATPase. Demonstration of this non-filament-based motility mechanism in a biological context establishes a distinct class of motor system used for the transport and positioning of large cellular cargo.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available