3D structure of EspA filaments from enteropathogenic <i>Escherichia coli</i>

Daniell, Sarah; Kocsis, Eva; Morris, Edward P.; Knutton, Stuart; Booy, Frank P.; Frankel, Gad

doi:10.1046/j.1365-2958.2003.03555.x

Cited by 94 publications

(100 citation statements)

References 52 publications

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“…EspA polymerizes into the filamentous structure, and its polymerization is dependent on coiled-coil interactions between the C-terminal region of the molecule (11) in a way similar to flagella assembly (9). EspB has been reported to interact with EspA (12,13) and EspD (14), and the complexes that form at the distal portion of the needle structure may act as a pore at the contact site with the host cell membrane and participate in the initial step of bacterial adherence (15).…”

Section: Enterohemorrhagic Escherichia Coli (Ehec)mentioning

confidence: 99%

Identification of a Third EspA-binding Protein That Forms Part of the Type III Secretion System of Enterohemorrhagic Escherichia coli

Ku¹,

Lio²,

Wang³

et al. 2009

Journal of Biological Chemistry

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Enterohemorrhagic Escherichia coli utilizes a type III secretion system to deliver virulent effectors into cells. The secretion apparatus comprises a membrane basal body and an external needle complex of which EspA is the major component. An l0050-deletion (⌬L50) mutation was found to impair type III secretion and bacterial adherence. These phenotypes and the localization of the gene product to the inner membrane support the hypothesis that L0050, renamed EscL, forms part of the secretion apparatus. Furthermore, in ⌬L50, the amount of EspA present within the cell lysate was found to have diminished, whereas the EspA co-cistron-expressed partner protein EspB remained unaffected. The decreased EspA level appeared to result from instability of the newly synthesized EspA protein in ⌬L50 rather than a decrease in EspA mRNA. Using both biochemical co-purification and a bacterial two-hybrid interaction system, we were able to conclude that EscL is a third protein that, in addition to CesAB and CesA2, interacts with EspA and enhances the stability of intracellular EspA.

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Section: Enterohemorrhagic Escherichia Coli (Ehec)mentioning

confidence: 99%

Identification of a Third EspA-binding Protein That Forms Part of the Type III Secretion System of Enterohemorrhagic Escherichia coli

Ku¹,

Lio²,

Wang³

et al. 2009

Journal of Biological Chemistry

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“…It was shown that the upper half of the C-terminal ␣-helix of one flagellin subunit interacts with the lower half of the C-terminal ␣-helix of an adjacent flagellin subunit (35). Considering the apparently identical subunit arrangements in the needle (36), the EspA filament (11), and the flagellum (35), it would not be surprising that general features of subunit-subunit interactions would be conserved in all TTSS-associated filaments.…”

Section: Toward Understanding the Molecular Defects Of Nonfunctional mentioning

confidence: 99%

“…For example, the TTSS of mammalian pathogenic bacteria assembles a needle complex, which consists of a base structure embedded in the bacterial cell wall and a primarily extracellular hollow needle of 6 -8 nm in diameter and 50 -80 nm in length (5-10). In enteropathogenic Escherichia coli, the needle is connected with another extracellular filament called the EspA filament (11,12). The EspA filament is 12 nm in diameter and can be several micrometers long (13,14).…”

mentioning

confidence: 99%

Use of Dominant-negative HrpA Mutants to Dissect Hrp Pilus Assembly and Type III Secretion in Pseudomonas syringae pv. tomato

Lee

Kolade²,

Nomura³

et al. 2005

Journal of Biological Chemistry

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The Hrp pilus plays an essential role in the long-distance type III translocation of effector proteins from bacteria into plant cells. HrpA is the structural subunit of the Hrp pilus in Pseudomonas syringae pv. tomato (Pst) DC3000. Little is known about the molecular features in the HrpA protein for pilus assembly or for transporting effector proteins. From previous collections of nonfunctional HrpA derivatives that carry random pentapeptide insertions or single amino acid mutations, we identified several dominant-negative mutants that blocked the ability of wild-type Pst DC3000 to elicit host responses. The dominant-negative phenotype was correlated with the disappearance of the Hrp pilus in culture and inhibition of wild-type HrpA protein self-assembly in vitro. Dominant-negative HrpA mutants can be grouped into two functional classes: one class exerted a strong dominant-negative effect on the secretion of effector proteins AvrPto and HopPtoM in culture, and the other did not. The two classes of mutant HrpA proteins carry pentapeptide insertions in discrete regions, which are interrupted by insertions without a dominant-negative effect. These results enable prediction of possible subunit-subunit interaction sites in the assembly of the Hrp pilus and suggest the usefulness of dominant-negative mutants in dissection of the role of the wild-type HrpA protein in various stages of type III translocation: protein exit across the bacterial cell wall, the assembly and/or stabilization of the Hrp pilus in the extracellular space, and Hrp pilus-mediated long-distance transport beyond the bacterial cell wall. The bacterial type III secretion system (TTSS)1 is a longdistance protein transport system, moving bacterial effector proteins from the bacterial cytoplasm into a eukaryotic cell (1-4). During this long-distance transport, several physical barriers must be traversed: the bacterial cell wall, the host extracellular matrix layer (e.g. plant cell wall or animal mucous layer/glycocalyx), and the host plasma membrane. The TTSS has adapted to such long-distance transport by assembling extracellular needle/pilus-like appendages of various lengths (3, 4). For example, the TTSS of mammalian pathogenic bacteria assembles a needle complex, which consists of a base structure embedded in the bacterial cell wall and a primarily extracellular hollow needle of 6 -8 nm in diameter and 50 -80 nm in length (5-10). In enteropathogenic Escherichia coli, the needle is connected with another extracellular filament called the EspA filament (11,12). The EspA filament is 12 nm in diameter and can be several micrometers long (13,14). The TTSS of plant pathogenic bacteria assembles an extracellular appendage called the Hrp pilus, which is 6 -8 nm wide and several micrometers long (15-20). The needle, EspA filament, and Hrp pilus are believed to be tunnels linking the type III "secreton" embedded in the bacterial cell wall and a type III "translocon" in the host plasma membrane. The secreton allows the exit of effector proteins across the bacte...

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“…In addition to these common structures, the LEE-encoded TTSS possesses a long filamentous structure that connects the distal end of the needle structure to the host cell membrane (Knutton et al, 1998;Daniell et al, 2001;Sekiya et al, 2001;Wilson et al, 2001). The filament is composed of many copies of EspA forming a helical bundle with a central pore through which secreted proteins may pass (Daniell et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

CesAB is an enteropathogenic Escherichia coli chaperone for the type-III translocator proteins EspA and EspB

et al. 2003

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Enteropathogenic Escherichia coli (EPEC) are extracellular pathogens that colonize mucosal surfaces of the intestine via formation of attaching and effacing (A/E) lesions. The genes responsible for induction of the A/E lesions are located on a pathogenicity island, termed the locus of enterocyte effacement (LEE), which encodes the adhesin intimin and the type III secretion system needle complex, translocator and effector proteins. One of the major EPEC translocator proteins, EspA, forms a filamentous conduit along which secreted proteins travel before they arrive at the translocation pore in the plasma membrane of the host cell, which is composed of EspB and EspD. Prior to secretion, many type III proteins, including translocators, are maintained in the bacterial cytoplasm by association with a specific chaperone. In EPEC, chaperones have been identified for the effector proteins Tir, Map and EspF, and the translocator proteins EspD and EspB. In this study, CesAB (Orf3 of the LEE) was identified as a chaperone for EspA and EspB. Specific CesAB–EspA and CesAB–EspB protein interactions are demonstrated. CesAB was essential for stability of EspA within the bacterial cell prior to secretion. Furthermore, a cesAB mutant failed to secrete EspA, as well as EspB, to assemble EspA filaments, to induce A/E lesion following infection of HEp-2 cells and to adhere to, or cause haemolysis of, erythrocytes.

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3D structure of EspA filaments from enteropathogenic Escherichia coli

Cited by 94 publications

References 52 publications

Identification of a Third EspA-binding Protein That Forms Part of the Type III Secretion System of Enterohemorrhagic Escherichia coli

Identification of a Third EspA-binding Protein That Forms Part of the Type III Secretion System of Enterohemorrhagic Escherichia coli

Use of Dominant-negative HrpA Mutants to Dissect Hrp Pilus Assembly and Type III Secretion in Pseudomonas syringae pv. tomato

CesAB is an enteropathogenic Escherichia coli chaperone for the type-III translocator proteins EspA and EspB

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