The bacterial actin MreB rotates, and rotation depends on cell-wall assembly. Author Sven van Teeffelen, Siyuan Wang, Leon Furchtgott, Kerwyn Huang, Ned Wingreen, Joshua Shaevitz, Zemer Gitai Publication Year 2011 Type Journal Article Abstract Bacterial cells possess multiple cytoskeletal proteins involved in a wide range of cellular processes. These cytoskeletal proteins are dynamic, but the driving forces and cellular functions of these dynamics remain poorly understood. Eukaryotic cytoskeletal dynamics are often driven by motor proteins, but in bacteria no motors that drive cytoskeletal motion have been identified to date. Here, we quantitatively study the dynamics of the Escherichia coli actin homolog MreB, which is essential for the maintenance of rod-like cell shape in bacteria. We find that MreB rotates around the long axis of the cell in a persistent manner. Whereas previous studies have suggested that MreB dynamics are driven by its own polymerization, we show that MreB rotation does not depend on its own polymerization but rather requires the assembly of the peptidoglycan cell wall. The cell-wall synthesis machinery thus either constitutes a novel type of extracellular motor that exerts force on cytoplasmic MreB, or is indirectly required for an as-yet-unidentified motor. Biophysical simulations suggest that one function of MreB rotation is to ensure a uniform distribution of new peptidoglycan insertion sites, a necessary condition to maintain rod shape during growth. These findings both broaden the view of cytoskeletal motors and deepen our understanding of the physical basis of bacterial morphogenesis. Keywords Escherichia coli, Actins, Models, Biological, Computer Simulation, Escherichia coli Proteins, Kinetics, Microscopy, Fluorescence, Rotation, Cell Wall, Luminescent Proteins, Anti-Bacterial Agents, Peptidoglycan, Peptides, Dose-Response Relationship, Drug, Vancomycin, Amdinocillin, Depsipeptides, Glycosylation Journal Proc Natl Acad Sci U S A Volume 108 Issue 38 Pages 15822-7 Date Published 09/2011 Alternate Journal Proc. Natl. Acad. Sci. U.S.A. Google ScholarBibTeXEndNote X3 XML