MotAB-like machinery drives the movement of MreB filaments during bacterial gliding motility

Abstract

MreB is a bacterial actin that is important for cell shape and cell wall biosynthesis in many bacterial species. MreB also plays crucial roles in gliding motility, but the underlying mechanism remains unknown. Here we tracked the dynamics of single MreB particles in using single-particle tracking photoactivated localization microscopy. We found that a subpopulation of MreB particles moves rapidly along helical trajectories, similar to the movements of the MotAB-like gliding motors. The rapid MreB motion was stalled in the mutants that carried truncated gliding motors. Remarkably, MreB moves one to two orders of magnitude faster than its homologs that move along with the cell wall synthesis machinery in and , and this rapid movement was not affected by the inhibitors of cell wall biosynthesis. Our results show that in, MreB provides a scaffold for the gliding motors while the gliding machinery drives the movement of MreB filaments, analogous to the interdependent movements of myosin motors and actin in eukaryotic cells.

Omnipresent Maxwell's demons orchestrate information management in living cells

“…Within the frame of the present work, pointing out that information maintenance will require MxD-like nanomachines, we may investigate whether such functional entities could indeed be identified in the formation of the cell's poles for example. Among many possibilities, oscillating factors such as MreB actin-like protein define the poles in association with a variety of other factors (Colavin et al, 2018;Fu et al, 2018;Shi et al, 2018). The details of shape formation would require specific factors acting as MxDs.…”

Establishing Rod-Shape from Spherical, Peptidoglycan-Deficient Bacterial Spores

“…MglA and MglB are both cytoplasmic proteins, which are not likely to regulate the enzymatic activities of the Rod system directly. To investigate whether MglA and MglB regulate the distribution of the Rod complexes, we used a fully functional, photoactivatable mCherry (PAmCherry)-labeled MreB variant (17) to mark the localization of Rod complexes in germination Phase II. When the majority of PAmCherry was photoactivated, MreB-PAmCherry appeared as small patches (17) (Fig.…”

“…MglA connects MreB to the gliding motors and the gliding motors drive the movement of MreB filaments (16, 17, 20). To test if MglA recruits the gliding motors to transport the Rod complexes to nonpolar locations through MreB, we investigated the regrowth process of the ΔaglQS pseudospores.…”

“…To test if MglA recruits the gliding motors to transport the Rod complexes to nonpolar locations through MreB, we investigated the regrowth process of the ΔaglQS pseudospores. ΔaglQS cells carry truncated gliding motors that are unable to drive the rapid motion of MreB filaments (17). Due to the truncation of motors, the ΔaglQS pseudospores lack compact polysaccharide layers on their surfaces (32).…”

“…The motors for gliding assemble into functional machineries on MreB filaments (12–16). Consequently, the gliding machineries carry MreB filaments as they move rapidly in the membrane (17). As cells move, GTP-bound MglA forms large clusters at leading cell poles, whereas GDP-bound MglA distributes homogeneously in the cytoplasm (16, 18, 19).…”