A partial atomic structure for the flagellar hook of
            <i>Salmonella typhimurium</i>

Shaikh, Tanvir R.; Thomas, Dennis R.; Chen, James Z.; Samatey, Fadel A.; Matsunami, Hiroyuki; Imada, Katsumi; Namba, Keiichi; DeRosier, David J.

doi:10.1073/pnas.0409020102

Cited by 50 publications

(62 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The electron cryomicroscopy structure of the Salmonella enterica serovar Typhimurium hook (17), which is 88% homologous to the E. coli FlgE protein, shows that only a central segment from A146 to K284 (D2 domain, E. coli numbers) lies on the outside of the assembled hook structure. Since successful insertion of the AviTag in nonterminal regions has been achieved previously (1, 14, 26), we chose sites in positions that had limited similarity across different species (31). Based on this information, five insertion sites for the AviTag were chosen, three of which were in loops (Fig.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Flagellar Hook Flexibility Is Essential for Bundle Formation in Swimming Escherichia coli Cells

et al. 2012

View full text Add to dashboard Cite

dSwimming Escherichia coli cells are propelled by the rotary motion of their flagellar filaments. In the normal swimming pattern, filaments positioned randomly over the cell form a bundle at the posterior pole. It has long been assumed that the hook functions as a universal joint, transmitting rotation on the motor axis through up to ϳ90 o to the filament in the bundle. Structural models of the hook have revealed how its flexibility is expected to arise from dynamic changes in the distance between monomers in the helical lattice. In particular, each of the 11 protofilaments that comprise the hook is predicted to cycle between short and long forms, corresponding to the inside and outside of the curved hook, once each revolution of the motor when the hook is acting as a universal joint. To test this, we genetically modified the hook so that it could be stiffened by binding streptavidin to biotinylated monomers, impeding their motion relative to each other. We found that impeding the action of the universal joint resulted in atypical swimming behavior as a consequence of disrupted bundle formation, in agreement with the universal joint model. An Escherichia coli cell swimming is arguably one of the simplest examples of behavior in a living organism. As a consequence, much is understood about the system: the process of flagellum assembly (8), the motor's molecular architecture (25) and physiology (3,32), and the physics of swimming (7, 29). The flagellum is a macromolecular complex made up of ϳ30 different proteins (3), which are assembled in a particular order (8). It can be divided into three parts: the motor, the hook, and the filament. The motor is embedded in the cell envelope, spanning both the inner and outer membranes. In E. coli, motor rotation is powered by the diffusion of protons from the periplasm, down their electrochemical potential gradient, and into the cytoplasm (32). The motor is coupled via the hook to the filament. The hook consists of a flexible curved helical structure 55 nm long (19), made up of ϳ120 copies of the FlgE protein which form 11 helical protofilaments (12,13,33). The filament also consists of a single protein (FliC) made into 11 protofilaments, but it is 10 to 15 m long and rigid for its function as a propeller (3). An E. coli cell typically possesses ϳ4 to 10 flagella which coalesce to form a bundle at the posterior pole when swimming. When one or more motors reverse direction in response to environmental cues, they break from the bundle, causing the cell to reorientate (10).The hook is thought to act as a universal joint, translating rotation from the axis of rotation at the motor, through 90 o , to the filament participating in the bundle. This idea was first postulated by Berg and Anderson in 1973 (4). Since then, models describing the universal joint have been developed based on ever-advancing structural information (17,30,31). FlgE is composed of four domains (D0, Dc, D1, and D2) positioned radially from the inside to the outside of the hook (17). The D0 domains form the inn...

show abstract

Section: Resultsmentioning

confidence: 99%

“…This idea was first postulated by Berg and Anderson in 1973 (4). Since then, models describing the universal joint have been developed based on ever-advancing structural information (17,30,31). FlgE is composed of four domains (D0, Dc, D1, and D2) positioned radially from the inside to the outside of the hook (17).…”

mentioning

confidence: 99%

Flagellar Hook Flexibility Is Essential for Bundle Formation in Swimming Escherichia coli Cells

et al. 2012

View full text Add to dashboard Cite

show abstract

“…It is still unclear whether the inner diameter of the hook, which is smaller than 2 nm, allows the simultaneous passage of FliK and the hook protein FlgE (498). It was therefore proposed that FliK acts as a more flexible ruler molecule that is constantly secreted through the growing hook structure and switches the substrate specificity when the hook has reached its final length (159) (Fig.…”

Section: T3s Substrate Specificity Switching In Flagellar T3s Systemsmentioning

confidence: 99%

Protein Export According to Schedule: Architecture, Assembly, and Regulation of Type III Secretion Systems from Plant- and Animal-Pathogenic Bacteria

Büttner

2012

Microbiol Mol Biol Rev

366

482

View full text Add to dashboard Cite

SUMMARY Flagellar and translocation-associated type III secretion (T3S) systems are present in most Gram-negative plant- and animal-pathogenic bacteria and are often essential for bacterial motility or pathogenicity. The architectures of the complex membrane-spanning secretion apparatuses of both systems are similar, but they are associated with different extracellular appendages, including the flagellar hook and filament or the needle/pilus structures of translocation-associated T3S systems. The needle/pilus is connected to a bacterial translocon that is inserted into the host plasma membrane and mediates the transkingdom transport of bacterial effector proteins into eukaryotic cells. During the last 3 to 5 years, significant progress has been made in the characterization of membrane-associated core components and extracellular structures of T3S systems. Furthermore, transcriptional and posttranscriptional regulators that control T3S gene expression and substrate specificity have been described. Given the architecture of the T3S system, it is assumed that extracellular components of the secretion apparatus are secreted prior to effector proteins, suggesting that there is a hierarchy in T3S. The aim of this review is to summarize our current knowledge of T3S system components and associated control proteins from both plant- and animal-pathogenic bacteria.

show abstract

“…A partial atomic hook model was obtained by docking the crystal structure of the FlgE31 fragment into a 3D-EM density map of a straight hook (Samatey et al 2004;Shaikh et al 2005) (Fig. 9A).…”

Section: Structures Of Extracellular Appendages: the Flagellar Hook mentioning

confidence: 99%

Bacterial Nanomachines: The Flagellum and Type III Injectisome

Erhardt

Namba²,

Hughes

2010

Cold Spring Harbor Perspectives in Biology

226

204

View full text Add to dashboard Cite

The bacterial flagellum and the virulence-associated injectisome are complex, structurally related nanomachines that bacteria use for locomotion or the translocation of virulence factors into eukaryotic host cells. The assembly of both structures and the transfer of extracellular proteins is mediated by a unique, multicomponent transport apparatus, the type III secretion system. Here, we discuss the significant progress that has been made in recent years in the visualization and functional characterization of many components of the type III secretion system, the structure of the bacterial flagellum, and the injectisome complex.

show abstract

A partial atomic structure for the flagellar hook of Salmonella typhimurium

Cited by 50 publications

References 35 publications

Flagellar Hook Flexibility Is Essential for Bundle Formation in Swimming Escherichia coli Cells

Flagellar Hook Flexibility Is Essential for Bundle Formation in Swimming Escherichia coli Cells

Protein Export According to Schedule: Architecture, Assembly, and Regulation of Type III Secretion Systems from Plant- and Animal-Pathogenic Bacteria

Bacterial Nanomachines: The Flagellum and Type III Injectisome

Contact Info

Product

Resources

About