Channel Formation by FhaC, the Outer Membrane Protein Involved in the Secretion of the Bordetella pertussis Filamentous Hemagglutinin

Jacob‐Dubuisson, Françoise; El-Hamel, Chahrazed; Saint, Nathalie; Guédin, Sandrine; Willery, Eve; Molle, Gérard; Locht, Camille

doi:10.1074/jbc.274.53.37731

Cited by 93 publications

(89 citation statements)

References 38 publications

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“…However, previous studies performed with bacterial Omp85-like proteins have not supported this notion. Although several bacterial family members have been demonstrated to have pore activity, none had been found to be multimeric (7,15,16). Immunoblot analysis revealed that N. meningitidis Omp85 exists in a high-molecular weight complex (7); however, earlier work by Manning et al demonstrated that this protein interacts with several heterologous proteins in the OM (44), thus precluding any conclusion regarding the structural organization of N. meningitidis Omp85.…”

Section: Discussionmentioning

confidence: 85%

“…In bacteria, the only two family members that have been studied in detail are ShlB and FhaC, both of which have been demonstrated to have pore activity. However, no convincing evidence for multimer formation has been obtained for either ShlB or FhaC, thus contrasting with eukaryotic Omp85-like proteins (15,16). These findings have led others to suggest that the tetrameric Omp85 protein translocation system in eukaryotes may have evolved from more primitive, monomeric bacterial Omp85 homologs (3,5).…”

mentioning

confidence: 70%

“…The specific activity of the HMW1B proteoliposome for arabinose was Ϸ0.019 ⌬A400 per min͞ g, which is considerably lower than that of OmpF (35). This low specific activity raises the possibility that HMW1B in the proteoliposome is intermittently in a closed or otherwise nonfunctional conformation (16,34).…”

Section: Hmw1b Likely Forms a ␤-Barrelmentioning

confidence: 99%

“…We have suggested (17) that HMW1 is translocated to the bacterial surface by HMW1B. To test whether HMW1B forms a conduit in the OM to facilitate translocation, we examined HMW1B by using the liposomeswelling assay, which has been used previously to study the pore-forming activities of bacterial porins and several proteinspecific translocators (16,27,(31)(32)(33)(34). As shown in Fig.…”

Section: Hmw1b Likely Forms a ␤-Barrelmentioning

confidence: 99%

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Evidence for conservation of architecture and physical properties of Omp85-like proteins throughout evolution

Surana

Grass

Hardy

et al. 2004

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

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Omp85-like proteins represent a family of proteins involved in protein translocation, and they are present in all domains of life, except archaea. In eukaryotes, Omp85-like proteins have been demonstrated to form tetrameric pore-forming complexes that interact directly with their substrate proteins. Studies performed with bacterial Omp85-like proteins have demonstrated pore-forming activity but no evidence of multimerization. In this article, we characterize the Haemophilus influenzae HMW1B protein, an Omp85-like protein that has been demonstrated to be critical for secretion of the H. influenzae HMW1 adhesin. Analysis of purified protein by biochemical and electron microscopic techniques revealed that HMW1B forms a tetramer. Examination using liposomeswelling assays demonstrated that HMW1B has pore-forming activity, with a pore size of Ϸ2.7 nm. Far-Western blot analysis established that HMW1B interacts with the N terminus of HMW1. These results provide evidence that a bacterial Omp85-like protein forms a tetramer and interacts directly with a substrate protein, suggesting that the architecture and physical properties of Omp85-like proteins have been conserved throughout evolution. O mp85-like proteins represent a large family defined by phylogenetic relatedness, secondary-structure predictions, and a role in protein translocation (1-5). Members of this family are present in diverse organisms across the evolutionary spectrum, including bacteria, fungi, plants, and animals (1, 4). The widespread nature of Omp85-like proteins underscores their critical role in cellular processes, highlighted by the fact that many are required for cell viability (3,4,(6)(7)(8)(9). Although all Omp85-like proteins share sequence homology, they can be grouped into two classes based on the specific role that they play in protein translocation. One class is typified by Saccharomyces cerevisiae Sam50 and Neurospora crassa Tob55, which are chiefly involved in insertion of ␤-barrel proteins into the outer membrane (OM) of mitochondria (6, 9). The second class is epitomized by the chloroplast protein Toc75, which is involved in secretion of proteins across a membrane (10, 11). Interestingly, both classes of Omp85-like proteins are present in Gramnegative bacteria. Neisseria meningitidis Omp85, the namesake of this family of proteins, has been demonstrated recently to be critical for the insertion of proteins into the bacterial OM (7). Other Gram-negative bacterial Omp85-like proteins, including Serratia marcescens ShlB and Bordetella pertussis FhaC [and other members of the so-called two-partner secretion (TPS) pathway], have been demonstrated to function in protein export across the OM (12).The high level of amino acid homology among Omp85-like proteins from bacteria to humans raises the possibility that members of this family have similar structures. Although no crystal structures exist so far for Omp85-like proteins, several of these proteins have been subjected to biochemical studies of overall architecture. In eukaryotes, both classes...

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Section: Discussionmentioning

confidence: 85%

mentioning

confidence: 70%

Section: Hmw1b Likely Forms a ␤-Barrelmentioning

confidence: 99%

Section: Hmw1b Likely Forms a ␤-Barrelmentioning

confidence: 99%

See 2 more Smart Citations

Evidence for conservation of architecture and physical properties of Omp85-like proteins throughout evolution

Surana

Grass

Hardy

et al. 2004

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

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“…PTBs of recent interest are, e.g. outer membrane proteins (which secrete adhesins such as hemagglutinin) (8,9) and bacterial (1, 7, 10 -12), mitochondrial (Tob55/Sam50) (5,13,14), and chloroplast outer membrane proteins (Toc75) (15) of the Omp85 family. The PTBs are partitioned into two functional categories, namely in translocation of precursor proteins across the membrane and in the assembly of outer membrane proteins (3).…”

mentioning

confidence: 99%

Functional and Phylogenetic Properties of the Pore-forming β-Barrel Transporters of the Omp85 Family

Bredemeier

Schlegel

Ertel

et al. 2007

Journal of Biological Chemistry

101

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␤-Barrel-shaped channels of the Omp85 family are involved in the translocation or assembly of proteins of bacterial, mitochondrial, and plastidic outer membranes. We have compared these proteins to understand the evolutionary development of the translocators. We have demonstrated that the proteins from proteobacteria and mitochondria have a pore diameter that is at least five times smaller than found for the Omp85 in cyanobacteria and plastids. This finding can explain why Omp85 from cyanobacteria (but not the homologous protein from proteobacteria) was remodeled to become the protein translocation pore after endosymbiosis. Further, the pore-forming region of the Omp85 proteins is restricted to the C terminus. Based on a phylogenetic analysis we have shown that the pore-forming domain displays a different evolutionary relationship than the N-terminal domain. In line with this, the affinity of the N-terminal domain to the C-terminal region of the Omp85 from plastids and cyanobacteria differs, even though the N-terminal domain is involved in gating of the pore in both groups. We have further shown that the N-terminal domain of nOmp85 takes part in homo-oligomerization. Thereby, the differences in the phylogeny of the two domains are explained by different functional constraints acting on the regions. The poreforming domain, however, is further divided into two functional regions, where the distal C terminus itself forms a dimeric pore. Based on functional and phylogenetic analysis, we suggest an evolutionary scenario that explains the origin of the contemporary translocon.Polypeptide transport and assembly of proteins into or across the outer membrane of endosymbiotic organelles or Gram-negative bacteria depend on ␤-barrel-shaped channels (1-4). One class of these proteins is composed of polypeptide-transporting ␤-barrel (PTB) 6 channels, whose topology was determined by modeling (5-7). PTBs of recent interest are, e.g. outer membrane proteins (which secrete adhesins such as hemagglutinin) (8, 9) and bacterial (1, 7, 10 -12), mitochondrial (Tob55/Sam50) (5, 13, 14), and chloroplast outer membrane proteins (Toc75) (15) of the Omp85 family. The PTBs are partitioned into two functional categories, namely in translocation of precursor proteins across the membrane and in the assembly of outer membrane proteins (3). Furthermore, comparison between chloroplastic, mitochondrial, and bacterial Omp85 protein sequences revealed a high similarity of these PTBs (14,16,17).The PTB Toc75 forms a complex with Toc34, Toc64, and Toc159 (3). A precursor protein-binding site at Toc75 (15, 18), together with the action of Toc159 (19), facilitates the translocation of precursor proteins across the membrane. In contrast, the Omp85 proteins from Neisseria meningitidis, Escherichia coli, and mitochondria are involved in the assembly of outer membrane proteins (1,5,7,(11)(12)(13)(14). As found for Toc75, the mitochondrial PTB is a component of a larger complex with Mas37 (20, 13) and Tob38/Sam35 (21,22).Recently, it was demonstrated that t...

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Structural and functional characterization of Solanum tuberosum VDAC36

et al. 2019

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As it forms water-filled channel in the mitochondria outer membrane and diffuses essential metabolites such as NADH and ATP, the VDAC (voltage-dependent anion channel) protein family plays a central role in all eukaryotic cells. In comparison with their mammalian homologues, little is known about the structural and functional properties of plant VDACs. In the present contribution, one of the two VDACs isoforms of Solanum tuberosum, stVDAC36, has been successfully overexpressed and refolded by an in-house method, as demonstrated by the information on its secondary and tertiary structure gathered from circular dichroism and intrinsic fluorescence. Cross-linking and molecular modelling studies have evidenced the presence of dimers and tetramers, and they suggest the formation of an intermolecular disulphide bond between two stVDAC36 monomers. The pore-forming activity was also assessed by liposome swelling assays, indicating a typical pore diameter between 2.0 and 2.7 nm. Finally, insights about the ATP binding inside the pore are given by docking studies and electrostatic calculations.

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Channel Formation by FhaC, the Outer Membrane Protein Involved in the Secretion of the Bordetella pertussis Filamentous Hemagglutinin

Cited by 93 publications

References 38 publications

Evidence for conservation of architecture and physical properties of Omp85-like proteins throughout evolution

Evidence for conservation of architecture and physical properties of Omp85-like proteins throughout evolution

Functional and Phylogenetic Properties of the Pore-forming β-Barrel Transporters of the Omp85 Family

Structural and functional characterization of Solanum tuberosum VDAC36

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