scholarly journals Dynamic Assembly/Disassembly of Staphylococcus aureus FtsZ Visualized by High-Speed Atomic Force Microscopy

2021 ◽  
Vol 22 (4) ◽  
pp. 1697
Author(s):  
Junso Fujita ◽  
Shogo Sugiyama ◽  
Haruna Terakado ◽  
Maho Miyazaki ◽  
Mayuki Ozawa ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Cell Division ◽  
Bacterial Cell ◽  
High Speed ◽  
Process Development ◽  
Imaging Techniques ◽  
Bacterial Cell Division ◽  
Force Microscopy ◽  
Atomic Force ◽  
Dynamic Assembly

FtsZ is a key protein in bacterial cell division and is assembled into filamentous architectures. FtsZ filaments are thought to regulate bacterial cell division and have been investigated using many types of imaging techniques such as atomic force microscopy (AFM), but the time scale of the method was too long to trace the filament formation process. Development of high-speed AFM enables us to achieve sub-second time resolution and visualize the formation and dissociation process of FtsZ filaments. The analysis of the growth and dissociation rates of the C-terminal truncated FtsZ (FtsZt) filaments indicate the net growth and dissociation of FtsZt filaments in the growth and dissociation conditions, respectively. We also analyzed the curvatures of the full-length FtsZ (FtsZf) and FtsZt filaments, and the comparative analysis indicated the straight-shape preference of the FtsZt filaments than those of FtsZf. These findings provide insights into the fundamental dynamic behavior of FtsZ protofilaments and bacterial cell division.

Image acquisition for trolling-mode atomic force microscopy based on dynamical equations of motion

2020 ◽  
pp. 095440622097755
Author(s):  
Mohammadreza Sajjadi ◽  
Hossein Nejat Pishkenari ◽  
Gholamreza Vossoughi
Keyword(s):  
Atomic Force Microscopy ◽  
High Speed ◽  
Imaging Techniques ◽  
Equations Of Motion ◽  
Horizontal Displacement ◽  
Dynamical Equations ◽  
Force Microscopy ◽  
Atomic Force ◽  
Two Degree Of Freedom ◽  
Mode Atomic Force Microscopy

Trolling mode atomic force microscopy (TR-AFM) can considerably reduce the liquid-resonator interaction forces, and hence, has overcome many imaging problems in liquid environments. This mode increases the quality factor (QF) significantly compared with the conventional AFM operation in liquid; therefore, the duration to reach the steady-state periodic motion of the oscillating probe is relatively high. As a result, utilizing conventional imaging techniques, which are based on measuring the amplitude and phase, are significantly slower when compared to our proposed method. This research presents a high-speed scanning technique based on an estimation law to obtain the topography of various samples utilizing a two-degree-of-freedom model of TR-AFM. The effect of the nanoneedle tip horizontal displacement on the estimation process is investigated, and a solution to compensate for its undesirable effect is also presented.

scholarly journals Structural visualization of septum formation in Staphylococcus warneri using atomic force microscopy

2020 ◽  
Author(s):  
Hai-Nan Su ◽  
Kang Li ◽  
Xiao-Xue Yuan ◽  
Meng-Yao Zhang ◽  
Si-Min Liu ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Cell Division ◽  
Bacterial Cell ◽  
Structural Basis ◽  
Cell Cycles ◽  
Force Microscopy ◽  
Staphylococcus Warneri ◽  
Septum Formation ◽  
Atomic Force ◽  
Inner Surface

ABSTRACTCell division of Staphylococcus adopts a “popping” mechanism that mediates extremely rapid separation of the septum. Elucidating the structure of the septum is crucial for understanding this exceptional bacterial cell division mechanism. Here, the septum structure of Staphylococcus warneri is extensively characterized using high-speed time-lapse confocal microscopy, atomic force microscopy, and electron microscopy. The cells of S. warneri divide in a fast “popping” manner on a millisecond timescale. Our results show that the septum is composed of two separable layers, providing a structural basis for the ultrafast daughter cell separation. The septum is formed progressively toward the center with non-uniform thickness of the septal disk in radial directions. The peptidoglycan on the inner surface of double-layered septa is organized into concentric rings, which are generated along with septum formation. Moreover, this study signifies the importance of new septum formation in initiating new cell cycles. This work unravels the structural basis underlying the “popping” mechanism that drives Staphylococcus cell division and reveals a generic structure of the bacterial cell.IMPORTRANCEThis work shows that the septum of Staphylococcus warneri is composed of two layers and the peptidoglycan on the inner surface of the double-layered septum is organized into concentric rings. Moreover, new cell cycles of Staphylococcus could be initiated before the previous cell cycle is complete. This work advances our knowledge about a basic structure of bacterial cell and provides the double layered structural information of septum for the bacterium that divide with the “popping” mechanism.

scholarly journals Histone variant H2A.B-H2B dimers are spontaneously exchanged with canonical H2A-H2B in the nucleosome

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Rina Hirano ◽  
Yasuhiro Arimura ◽  
Tomoya Kujirai ◽  
Mikihiro Shibata ◽  
Aya Okuda ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Dna Repair ◽  
High Speed ◽  
Histone Chaperones ◽  
Histone H2a ◽  
Force Microscopy ◽  
Atomic Force ◽  
Open Conformation ◽  
Replication Sites ◽  
Histone Exchange

AbstractH2A.B is an evolutionarily distant histone H2A variant that accumulates on DNA repair sites, DNA replication sites, and actively transcribing regions in genomes. In cells, H2A.B exchanges rapidly in chromatin, but the mechanism has remained enigmatic. In the present study, we found that the H2A.B-H2B dimer incorporated within the nucleosome exchanges with the canonical H2A-H2B dimer without assistance from additional factors, such as histone chaperones and nucleosome remodelers. High-speed atomic force microscopy revealed that the H2A.B nucleosome, but not the canonical H2A nucleosome, transiently forms an intermediate “open conformation”, in which two H2A.B-H2B dimers may be detached from the H3-H4 tetramer and bind to the DNA regions near the entry/exit sites. Mutational analyses revealed that the H2A.B C-terminal region is responsible for the adoption of the open conformation and the H2A.B-H2B exchange in the nucleosome. These findings provide mechanistic insights into the histone exchange of the H2A.B nucleosome.

High-Speed Atomic Force Microscopy for Studying the Dynamic Behavior of Protein Molecules at Work

2006 ◽  
Vol 45 (3B) ◽  
pp. 1897-1903 ◽  
Author(s):  
Toshio Ando ◽  
Takayuki Uchihashi ◽  
Noriyuki Kodera ◽  
Atsushi Miyagi ◽  
Ryo Nakakita ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Dynamic Behavior ◽  
High Speed ◽  
Force Microscopy ◽  
Atomic Force ◽  
Protein Molecules
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