Identification of a Multicomponent Complex Required for Outer Membrane Biogenesis in Escherichia coli

Wu, Tao; Malinverni, Juliana C.; Ruiz, Natividad; Kim, Seokhee; Silhavy, Thomas J.; Kahne, Daniel

doi:10.1016/j.cell.2005.02.015

Cited by 683 publications

(943 citation statements)

References 43 publications

Supporting

Mentioning

905

Contrasting

Unclassified

Order By: Relevance

“…The remaining reading frames encode two proteins with a molecular weight below 85 kDa and a yet unknown function. Similar to the observations for the proteobacterial Omp85 protein (11,23,32), the nOmp85 assembles into higher oligomeric complexes in vivo, as determined by non-denaturing SDS-PAGE (Fig. 1B, lanes 2 and 4) and chemical cross-linking (not shown).…”

Section: Methodssupporting

confidence: 64%

“…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).…”

mentioning

confidence: 99%

See 1 more Smart Citation

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

View full text Add to dashboard Cite

␤-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...

show abstract

Section: Methodssupporting

confidence: 64%

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

View full text Add to dashboard Cite

show abstract

“…The folding and insertion of b-barrel proteins in the OM is mediated by the b-barrel assembly machinery (BAM) complex, which is composed of an integral membrane protein BamA (YaeT) and 4 accessory lipoproteins, BamB (YfgL), BamC (NlpB), BamD (YfiO) and BamE (SmpA). [21][22][23] Of those proteins solely BamA and BamD were found to be essential for viability in E. coli. 22,23 Although discrepancies exist in the literature, BAM complex proteins have recently been renamed.…”

Section: Introductionmentioning

confidence: 99%

TheKlebsiella pneumoniaeYfgL (BamB) lipoprotein contributes to outer membrane protein biogenesis, type-1 fimbriae expression, anti-phagocytosis, andin vivovirulence

et al. 2016

View full text Add to dashboard Cite

Klebsiella pneumoniae is an opportunistic pathogen that causes several kinds of infections, including pneumonia, bacteremia, urinary tract infection and community-acquired pyogenic liver abscess (PLA). Adhesion is the critical first step in the infection process. Our previous work demonstrated that the transcellular translocation is exploited by K. pneumoniae strains to migrate from the gut flora into other tissues, resulting in systemic infections. However, the initial stages of K. pneumoniae infection remain unclear. In this study, we demonstrated that a K. pneumoniae strain deleted for yfgL (bamB) exhibited reduced adherence to and invasion of host cells; changed biogenesis of major b-barrel outer membrane proteins; decreased transcriptional expression of type-1 fimbriae; and increased susceptibility to vancomycin and erythromycin. The yfgL deletion mutant also had reduced ability to against neutrophil phagocytosis; exhibited decreased induction of host IL-6 production; and was profoundly attenuated for virulence in a K. pneumoniae model of bacteremia. Thus, the K. pneumoniae YfgL lipoprotein mediates in outer membrane proteins biogenesis and is crucial for anti-phagocytosis and survival in vivo. These data provide a new insight for K. pneumoniae attachment and such knowledge could facilitate preventive therapies or alternative therapies against K. pneumoniae.

show abstract

“…Recently, a family of b-barrel proteins related to Omp85 (Outer membrane protein, 85 kD) from Neisseria meningitidis was found in the outer membranes of Gram-negative bacteria, mitochondria, and chloroplasts (Yen et al, 2002;Gentle et al, 2005). Some bacteria contain multiple Omp85-related proteins, with the different homologs playing distinct roles in protein secretion (Jacob-Dubuisson et al, 2004) or the sorting of b-barrel proteins to the outer membrane (Voulhoux et al, 2003;Wu et al, 2005). By contrast, there appears to be just a single functional Omp85 homolog in mitochondria (Sam50 [Sorting and assembly machinery, 50 kD]; alternatively, Tob55 [Topogenesis of b-barrel proteins, 55 kD]), and this mediates b-barrel insertion into the membrane (Kozjak et al, 2003;Paschen et al, 2003;Gentle et al, 2004), as well as the insertion of other outer membrane proteins (Stojanovski et al, 2007).…”

mentioning

confidence: 99%

The Omp85-Related Chloroplast Outer Envelope Protein OEP80 Is Essential for Viability in Arabidopsis

et al. 2008

View full text Add to dashboard Cite

b-Barrel proteins of the Omp85 (Outer membrane protein, 85 kD) superfamily exist in the outer membranes of Gram-negative bacteria, mitochondria, and chloroplasts. Prominent Omp85 proteins in bacteria and mitochondria mediate biogenesis of other b-barrel proteins and are indispensable for viability. In Arabidopsis (Arabidopsis thaliana) chloroplasts, there are two distinct types of Omp85-related protein: Toc75 (Translocon at the outer envelope membrane of chloroplasts, 75 kD) and OEP80 (Outer Envelope Protein, 80 kD). Toc75 functions as a preprotein translocation channel during chloroplast import, but the role of OEP80 remains elusive. We characterized three T-DNA mutants of the Arabidopsis OEP80 (AtOEP80) gene. Selectable markers associated with the oep80-1 and oep80-2 insertions segregated abnormally, suggesting embryo lethality of the homozygous genotypes. Indeed, no homozygotes were identified among .100 individuals, and heterozygotes of both mutants produced approximately 25% aborted seeds upon self-pollination. Embryo arrest occurred at a relatively late stage (globular embryo proper) as revealed by analysis using Nomarski optics microscopy. This is substantially later than arrest caused by loss of the principal Toc75 isoform, atToc75-III (two-cell stage), suggesting a more specialized role for AtOEP80. Surprisingly, the oep80-3 T-DNA (located in exon 1 between the first and second ATG codons of the open reading frame) did not cause any detectable developmental defects or affect the size of the AtOEP80 protein in chloroplasts. This indicates that the N-terminal region of AtOEP80 is not essential for the targeting, biogenesis, or functionality of the protein, in contrast with atToc75-III, which requires a bipartite targeting sequence.

show abstract

Identification of a Multicomponent Complex Required for Outer Membrane Biogenesis in Escherichia coli

Cited by 683 publications

References 43 publications

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

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

TheKlebsiella pneumoniaeYfgL (BamB) lipoprotein contributes to outer membrane protein biogenesis, type-1 fimbriae expression, anti-phagocytosis, andin vivovirulence

The Omp85-Related Chloroplast Outer Envelope Protein OEP80 Is Essential for Viability in Arabidopsis

Contact Info

Product

Resources

About