TY - JOUR
T1 - How myxobacteria glide
AU - Wolgemuth, Charles
AU - Hoiczyk, Egbert
AU - Kaiser, Dale
AU - Oster, George
N1 - Funding Information:
David Stokes and Mike Lewis are gratefully acknowledged for use of the electron microscope facility at the Skirball Institute of Biomolecular Medicine; and Yvonne Cheng (Stanford University) for continuous, excellent technical help. David Zusman and his lab were always available for valuable discussions. Tom Powers provided a wealth of perceptive criticisms to the manuscript. C.W. and G.O. were supported by National Science Foundation Grant DMS-9972826 and National Institutes of Health Grant GM59875-01A1; E.H. was supported by a HHMI postdoctoral fellowship; D.K. was supported by NIH grant GM23441.
PY - 2002/3/5
Y1 - 2002/3/5
N2 - Background: Many microorganisms, including myxobacteria, cyanobacteria, and flexibacteria, move by gliding. Although gliding always describes a slow surface-associated translocation in the direction of the cell's long axis, it can result from two very different propulsion mechanisms: social (S) motility and adventurous (A) motility. The force for S motility is generated by retraction of type 4 pili. A motility may be associated with the extrusion of slime, but evidence has been lacking, and how force might be generated has remained an enigma. Recently, nozzle-like structures were discovered in cyanobacteria from which slime emanated at the same rate at which the bacteria moved. This strongly implicates slime extrusion as a propulsion mechanism for gliding. Results: Here we show that similar but smaller nozzle-like structures are found in Myxococcus xanthus and that they are clustered at both cell poles, where one might expect propulsive organelles. Furthermore, light and electron microscopical observations show that slime is secreted in ribbons from the ends of cells. To test whether the slime propulsion hypothesis is physically reasonable, we construct a mathematical model of the slime nozzle to see if it can generate a force sufficient to propel M. xanthus at the observed velocities. The model assumes that the hydration of slime, a cationic polyelectrolyte, is the force-generating mechanism. Conclusions: The discovery of nozzle-like organelles in various gliding bacteria suggests their role in prokaryotic gliding. Our calculations and our observations of slime trails demonstrate that slime extrusion from such nozzles can account for most of the observed properties of A motile gliding.
AB - Background: Many microorganisms, including myxobacteria, cyanobacteria, and flexibacteria, move by gliding. Although gliding always describes a slow surface-associated translocation in the direction of the cell's long axis, it can result from two very different propulsion mechanisms: social (S) motility and adventurous (A) motility. The force for S motility is generated by retraction of type 4 pili. A motility may be associated with the extrusion of slime, but evidence has been lacking, and how force might be generated has remained an enigma. Recently, nozzle-like structures were discovered in cyanobacteria from which slime emanated at the same rate at which the bacteria moved. This strongly implicates slime extrusion as a propulsion mechanism for gliding. Results: Here we show that similar but smaller nozzle-like structures are found in Myxococcus xanthus and that they are clustered at both cell poles, where one might expect propulsive organelles. Furthermore, light and electron microscopical observations show that slime is secreted in ribbons from the ends of cells. To test whether the slime propulsion hypothesis is physically reasonable, we construct a mathematical model of the slime nozzle to see if it can generate a force sufficient to propel M. xanthus at the observed velocities. The model assumes that the hydration of slime, a cationic polyelectrolyte, is the force-generating mechanism. Conclusions: The discovery of nozzle-like organelles in various gliding bacteria suggests their role in prokaryotic gliding. Our calculations and our observations of slime trails demonstrate that slime extrusion from such nozzles can account for most of the observed properties of A motile gliding.
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U2 - 10.1016/S0960-9822(02)00716-9
DO - 10.1016/S0960-9822(02)00716-9
M3 - Article
C2 - 11882287
AN - SCOPUS:0037022531
SN - 0960-9822
VL - 12
SP - 369
EP - 377
JO - Current Biology
JF - Current Biology
IS - 5
ER -