Lesson plan
MreB
MreB is a protein found in bacteria that is a homolog of actin, a major component of the cytoskeleton in eukaryotes. MreB is one of the most widespread bacterial actin homologs, and together with the tubulin-like protein FtsZ and the intermediate-filament-like protein crescentin it is among the best-studied components of the prokaryotic cytoskeleton. The protein is best known for determining and maintaining the shape of non-spherical bacteria. It is a major determinant of rod shape and contributes to width control in many species, including Escherichia coli; in E. coli, defective MreB or treatment with the MreB inhibitor A22 causes cells to widen and can make them nearly spherical. In Bacillus subtilis, by contrast, cell diameter is set by the opposing actions of the Rod complex and class-A penicillin-binding proteins rather than by MreB alone. Inside the cell, MreB binds to the inner face of the cell membrane and assembles into short filaments. These filaments are part of a cell-wall–building machine, the Rod complex (or elongasome), and they move around the circumference of the cell as new peptidoglycan is inserted into the lateral wall, supporting the cell's elongation along its long axis while contributing to width control.
Article summary
MreB is a protein found in bacteria that is a homolog of actin, a major component of the cytoskeleton in eukaryotes. MreB is one of the most widespread bacterial actin homologs, and together with the tubulin-like protein FtsZ and the intermediate-filament-like protein crescentin it is among the best-studied components of the prokaryotic cytoskeleton. The protein is best known for determining and maintaining the shape of non-spherical bacteria. It is a major determinant of rod shape and contributes to width control in many species, including Escherichia coli; in E. coli, defective MreB or treatment with the MreB inhibitor A22 causes cells to widen and can make them nearly spherical. In Bacillus subtilis, by contrast, cell diameter is set by the opposing actions of the Rod complex and class-A penicillin-binding proteins rather than by MreB alone. Inside the cell, MreB binds to the inner face of the cell membrane and assembles into short filaments. These filaments are part of a cell-wall–building machine, the Rod complex (or elongasome), and they move around the circumference of the cell as new peptidoglycan is inserted into the lateral wall, supporting the cell's elongation along its long axis while contributing to width control.
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Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
Bibliography
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Key claims and bibliography are generated from the same tracked claims and sources as the article page.