Abstract
In vivo fluorescence microscopy studies of bacterial cells have shown that the bacterial shape-determining protein and actin homolog, MreB, forms cable-like structures that spiral around the periphery of the cell. The molecular structure of these cables has yet to be established. Here we show by electron microscopy that Thermatoga maritime MreB forms complex, several μm long multilayered sheets consisting of diagonally interwoven filaments in the presence of either ATP or GTP. This architecture, in agreement with recent rheological measurements on MreB cables, may have superior mechanical properties and could be an important feature for maintaining bacterial cell shape. MreB polymers within the sheets appear to be single-stranded helical filaments rather than the linear protofilaments found in the MreB crystal structure. Sheet assembly occurs over a wide range of pH, ionic strength, and temperature. Polymerization kinetics are consistent with a cooperative assembly mechanism requiring only two steps: monomer activation followed by elongation. Steady-state TIRF microscopy studies of MreB suggest filament treadmilling while high pressure small angle x-ray scattering measurements indicate that the stability of MreB polymers is similar to that of F-actin filaments. In the presence of ADP or GDP, long, thin cables formed in which MreB was arranged in parallel as linear proto filaments. This suggests that the bacterial cell may exploit various nucleotides to generate different filament structures within cables for specific MreB-based functions.
| Original language | English |
|---|---|
| Pages (from-to) | 15858-15865 |
| Number of pages | 8 |
| Journal | Journal of Biological Chemistry |
| Volume | 285 |
| Issue number | 21 |
| DOIs | |
| Publication status | Published - May 21 2010 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Cell Biology
Cite this
Filament structure, organization, and dynamics in MreB sheets. / Popp, David; Narita, Akihiro; Maeda, Kayo; Fujisawa, Tetsuro; Ghoshdastider, Umesh; Iwasa, Mitsusada; Maéda, Yuichiro; Robinson, Robert C.
In: Journal of Biological Chemistry, Vol. 285, No. 21, 21.05.2010, p. 15858-15865.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Filament structure, organization, and dynamics in MreB sheets
AU - Popp, David
AU - Narita, Akihiro
AU - Maeda, Kayo
AU - Fujisawa, Tetsuro
AU - Ghoshdastider, Umesh
AU - Iwasa, Mitsusada
AU - Maéda, Yuichiro
AU - Robinson, Robert C.
PY - 2010/5/21
Y1 - 2010/5/21
N2 - In vivo fluorescence microscopy studies of bacterial cells have shown that the bacterial shape-determining protein and actin homolog, MreB, forms cable-like structures that spiral around the periphery of the cell. The molecular structure of these cables has yet to be established. Here we show by electron microscopy that Thermatoga maritime MreB forms complex, several μm long multilayered sheets consisting of diagonally interwoven filaments in the presence of either ATP or GTP. This architecture, in agreement with recent rheological measurements on MreB cables, may have superior mechanical properties and could be an important feature for maintaining bacterial cell shape. MreB polymers within the sheets appear to be single-stranded helical filaments rather than the linear protofilaments found in the MreB crystal structure. Sheet assembly occurs over a wide range of pH, ionic strength, and temperature. Polymerization kinetics are consistent with a cooperative assembly mechanism requiring only two steps: monomer activation followed by elongation. Steady-state TIRF microscopy studies of MreB suggest filament treadmilling while high pressure small angle x-ray scattering measurements indicate that the stability of MreB polymers is similar to that of F-actin filaments. In the presence of ADP or GDP, long, thin cables formed in which MreB was arranged in parallel as linear proto filaments. This suggests that the bacterial cell may exploit various nucleotides to generate different filament structures within cables for specific MreB-based functions.
AB - In vivo fluorescence microscopy studies of bacterial cells have shown that the bacterial shape-determining protein and actin homolog, MreB, forms cable-like structures that spiral around the periphery of the cell. The molecular structure of these cables has yet to be established. Here we show by electron microscopy that Thermatoga maritime MreB forms complex, several μm long multilayered sheets consisting of diagonally interwoven filaments in the presence of either ATP or GTP. This architecture, in agreement with recent rheological measurements on MreB cables, may have superior mechanical properties and could be an important feature for maintaining bacterial cell shape. MreB polymers within the sheets appear to be single-stranded helical filaments rather than the linear protofilaments found in the MreB crystal structure. Sheet assembly occurs over a wide range of pH, ionic strength, and temperature. Polymerization kinetics are consistent with a cooperative assembly mechanism requiring only two steps: monomer activation followed by elongation. Steady-state TIRF microscopy studies of MreB suggest filament treadmilling while high pressure small angle x-ray scattering measurements indicate that the stability of MreB polymers is similar to that of F-actin filaments. In the presence of ADP or GDP, long, thin cables formed in which MreB was arranged in parallel as linear proto filaments. This suggests that the bacterial cell may exploit various nucleotides to generate different filament structures within cables for specific MreB-based functions.
UR - http://www.scopus.com/inward/record.url?scp=77952387843&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77952387843&partnerID=8YFLogxK
U2 - 10.1074/jbc.M109.095901
DO - 10.1074/jbc.M109.095901
M3 - Article
C2 - 20223832
AN - SCOPUS:77952387843
VL - 285
SP - 15858
EP - 15865
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 21
ER -