Helical Structure of the Needle of the Type III Secretion System of Shigella flexneri

Cordes, Frank; Komoriya, Kaoru; Larquet, Éric; Yang, Shixin; Egelman, Edward H.; Blocker, Ariel; Lea, Susan M.

doi:10.1074/jbc.m300091200

Cited by 167 publications

(174 citation statements)

References 24 publications

Supporting

Mentioning

159

Contrasting

Unclassified

Order By: Relevance

“…2 B and C), whereas the B molecule is not consistent with the observed needle density (CC ϭ 47% for optimized positioning of molecule B). Although the conformation of the B molecule may be induced by crystal packing, it is also possible that it reflects the structure of the needle subunit when the needle is in a different activation state from that for which we have an EM reconstruction (16,25). The C-terminal helix forms the outer shell of the needle core, whereas the PSNP loop directs the N-terminal helix to line the inner wall of the needle channel.…”

Section: Resultsmentioning

confidence: 99%

“…We have previously demonstrated, by x-ray fiber diffraction and EM, that the Shigella flexneri needle shares an identical helical architecture (Ϸ5.6 subunits per turn, 24-Å helical pitch) and inner channel diameter (Ϸ2 nm) with the flagellar rod, hook, and filament (16). This architectural similarity is maintained despite the subunit of the T3SS needle being four to five times smaller and displaying no primary sequence homology with flagellar axial proteins.…”

mentioning

confidence: 86%

See 1 more Smart Citation

Molecular model of a type III secretion system needle: Implications for host-cell sensing

Deane

Roversi

Cordes

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

147

286

View full text Add to dashboard Cite

Type III secretion systems are essential virulence determinants for many Gram-negative bacterial pathogens. The type III secretion system consists of cytoplasmic, transmembrane, and extracellular domains. The extracellular domain is a hollow needle protruding above the bacterial surface and is held within a basal body that traverses both bacterial membranes. Effector proteins are translocated, via this external needle, directly into host cells, where they subvert normal cell functions to aid infection. Physical contact with host cells initiates secretion and leads to formation of a pore, thought to be contiguous with the needle channel, in the host-cell membrane. Here, we report the crystal structure of the Shigella flexneri needle subunit MxiH and a complete model for the needle assembly built into our three-dimensional EM reconstruction. The model, combined with mutagenesis data, reveals that signaling of host-cell contact is relayed through the needle via intersubunit contacts and suggests a mode of binding for a tip complex.needle complex ͉ protein secretion ͉ Shigella

show abstract

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 86%

Molecular model of a type III secretion system needle: Implications for host-cell sensing

Deane

Roversi

Cordes

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

147

286

View full text Add to dashboard Cite

show abstract

“…In addition to its role as an injectisome component, evidence suggests that the needle is also important in host cell detection and thus regulation of T3S (12,30,60). Electron micrographs of the needles from Yersinia, Salmonella Spi-1, and Shigella, comprising the small homologous proteins YscF, PrgI, and MxiH, respectively, reveal straight rigid structures that are very short (approximately 40 to 80 nm) compared to flagella (7,25,34,55). The crystal structure of monomeric MxiH has recently been solved revealing two extended antiparallel helices reminiscent of the D0 portion of flagellin (11,12).…”

mentioning

confidence: 99%

Bioinformatic and Biochemical Evidence for the Identification of the Type III Secretion System Needle Protein ofChlamydia trachomatis

et al. 2008

View full text Add to dashboard Cite

Chlamydia spp. express a functional type III secretion system (T3SS) necessary for pathogenesis and intracellular growth. However, certain essential components of the secretion apparatus have diverged to such a degree as to preclude their identification by standard homology searches of primary protein sequences. One example is the needle subunit protein. Electron micrographs indicate that chlamydiae possess needle filaments, and yet database searches fail to identify a SctF homologue. We used a bioinformatics approach to identify a likely needle subunit protein for Chlamydia. Experimental evidence indicates that this protein, designated CdsF, has properties consistent with it being the major needle subunit protein. CdsF is concentrated in the outer membrane of elementary bodies and is surface exposed as a component of an extracellular needle-like projection. During infection CdsF is detectible by indirect immunofluorescence in the inclusion membrane with a punctuate distribution adjacent to membrane-associated reticulate bodies. Biochemical cross-linking studies revealed that, like other SctF proteins, CdsF is able to polymerize into multisubunit complexes. Furthermore, we identified two chaperones for CdsF, termed CdsE and CdsG, which have many characteristics of the Pseudomonas spp. needle chaperones PscE and PscG, respectively. In aggregate, our data are consistent with CdsF representing at least one component of the extended Chlamydia T3SS injectisome. The identification of this secretion system component is essential for studies involving ectopic reconstitution of the Chlamydia T3SS. Moreover, we anticipate that CdsF could serve as an efficacious target for anti-Chlamydia neutralizing antibodies.

show abstract

“…The major extracellular portion of T3SSs is an approximately 50-nm-long, hollow needlelike structure, serving as a secretion conduit for effectors. The needle is made by the helical assembly of a single, small and conserved protein (3,4). It has been shown that the needle protein, MxiH in the enteropathogenic species Shigella, is directly involved in transducing the signal of host-cell contact to the base of the apparatus (5).…”

mentioning

confidence: 99%

Structure of a type III secretion needle at 7-Å resolution provides insights into its assembly and signaling mechanisms

Fujii

Cheung

Blanco

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

114

View full text Add to dashboard Cite

Type III secretion systems of Gram-negative bacteria form injection devices that deliver effector proteins into eukaryotic cells during infection. They span both bacterial membranes and the extracellular space to connect with the host cell plasma membrane. Their extracellular portion is a needle-like, hollow tube that serves as a secretion conduit for effector proteins. The needle of Shigella flexneri is approximately 50-nm long and 7-nm thick and is made by the helical assembly of one protein, MxiH. We provide a 7-Å resolution 3D image reconstruction of the Shigella needle by electron cryomicroscopy, which resolves α-helices and a β-hairpin that has never been observed in the crystal and solution structures of needle proteins, including MxiH. An atomic model of the needle based on the 3D-density map, in comparison with that of the bacterial-flagellar filament, provides insights into how such a thin tubular structure is stably assembled by intricate intermolecular interactions. The map also illuminates how the needle-length control protein functions as a ruler within the central channel during export of MxiH for assembly at the distal end of the needle, and how the secretion-activation signal may be transduced through a conformational change of the needle upon host-cell contact.helical image analysis | Shigella pathogenesis | bacterial protein secretion

show abstract

Helical Structure of the Needle of the Type III Secretion System of Shigella flexneri

Cited by 167 publications

References 24 publications

Molecular model of a type III secretion system needle: Implications for host-cell sensing

Molecular model of a type III secretion system needle: Implications for host-cell sensing

Bioinformatic and Biochemical Evidence for the Identification of the Type III Secretion System Needle Protein ofChlamydia trachomatis

Structure of a type III secretion needle at 7-Å resolution provides insights into its assembly and signaling mechanisms

Contact Info

Product

Resources

About