PMID:15178751
| Citation |
Case, RB, Chang, YP, Smith, SB, Gore, J, Cozzarelli, NR and Bustamante, C (2004) The bacterial condensin MukBEF compacts DNA into a repetitive, stable structure. Science 305:222-7 |
|---|---|
| Abstract |
Condensins are conserved proteins containing SMC (structural maintenance of chromosomes) moieties that organize and compact chromosomes in an unknown mechanism essential for faithful chromosome partitioning. We show that MukBEF, the condensin in Escherichia coli, cooperatively compacts a single DNA molecule into a filament with an ordered, repetitive structure in an adenosine triphosphate (ATP) binding-dependent manner. When stretched to a tension of approximately 17 piconewtons, the filament extended in a series of repetitive transitions in a broad distribution centered on 45 nanometers. A filament so extended and held at a lower force recondensed in steps of 35 nanometers or its multiples; this cycle was repeatable even in the absence of ATP and free MukBEF. Remarkably, the pattern of transitions displayed by a given filament during the initial extension was identical in every subsequent extension. Hence, after being deformed micrometers in length, each filament returned to its original compact structure without the addition of energy. Incubation with topoisomerase I increased the rate of recondensation and allowed the structure to extend and reform almost reversibly, indicating that supercoiled DNA is trapped in the condensed structure. We suggest a new model for how MukBEF organizes the bacterial chromosome in vivo. |
| Links |
PubMed Online version:10.1126/science.1098225 |
| Keywords |
Adenosine Triphosphate/metabolism; Binding Sites; Chemistry, Physical; Chromosomal Proteins, Non-Histone/chemistry; Chromosomal Proteins, Non-Histone/metabolism; DNA Topoisomerases, Type I/metabolism; DNA, Bacterial/chemistry; DNA, Bacterial/metabolism; DNA, Superhelical/chemistry; DNA, Superhelical/metabolism; Dimerization; Escherichia coli/genetics; Escherichia coli Proteins/chemistry; Escherichia coli Proteins/metabolism; Lasers; Microspheres; Models, Chemical; Models, Molecular; Nucleic Acid Conformation; Physicochemical Phenomena; Protein Binding; Protein Conformation; Protein Subunits; Repressor Proteins/chemistry; Repressor Proteins/metabolism |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
References
See Help:References for how to manage references in EcoliWiki.