Structure of the reduced disulfide-bond isomerase DsbC from<i>Escherichia coli</i>

Banaszak, K.; Mechin, I.; Frost, Graham; Rypniewski, W.

doi:10.1107/s0907444904018359

Cited by 24 publications

(21 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…TrxA, however, is unable to promote proper plasmid transfer (Table 3), indicating a distinct functional difference between TrxA and TrbB. Disulfide bond isomerases, which typically exist as homodimers, generally contain distinct N-terminal dimerization domains (4,46,63). Structural alignments with homodimeric thioredoxin family members such as DsbC E.coli and DsbC R27 (see Fig.…”

Section: Discussionmentioning

confidence: 99%

“…This nonspecific oxidation can lead to either recurrence of the substrate's misfolded state (M) or a correctly folded state (F). TrbB becomes oxidized and therefore dependent on an inner membrane protein (potentially DsbD) for reactivation (4). When the secondary attack originates from the substrate protein (5), the substrate is released in an oxidized state.…”

Section: Figmentioning

confidence: 99%

See 1 more Smart Citation

TrbB from Conjugative Plasmid F Is a Structurally Distinct Disulfide Isomerase That Requires DsbD for Redox State Maintenance

et al. 2011

View full text Add to dashboard Cite

TrbB, a periplasmic protein encoded by the conjugative plasmid F, has a predicted thioredoxin-like fold and possesses a C-X-X-C redox active site motif. TrbB may function in the conjugative process by serving as a disulfide bond isomerase, facilitating proper folding of a subset of F-plasmid-encoded proteins in the periplasm. Previous studies have demonstrated that a ⌬trbB F plasmid in Escherichia coli lacking DsbC E.coli , its native disulfide bond isomerase, experiences a 10-fold decrease in mating efficiency but have not provided direct evidence for disulfide bond isomerase activity. Here we demonstrate that trbB can partially restore transfer of a variant of the distantly related R27 plasmid when both chromosomal and plasmid genes encoding disulfide bond isomerases have been disrupted. In addition, we show that TrbB displays both disulfide bond isomerase and reductase activities on substrates not involved in the conjugative process. Unlike canonical members of the disulfide bond isomerase family, secondary structure predictions suggest that TrbB lacks both an N-terminal dimerization domain and an ␣-helical domain found in other disulfide bond isomerases. Phylogenetic analyses support the conclusion that TrbB belongs to a unique family of plasmid-based disulfide isomerases. Interestingly, although TrbB diverges structurally from other disulfide bond isomerases, we show that like those isomerases, TrbB relies on DsbD from E. coli for maintenance of its C-X-X-C redox active site motif.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Figmentioning

confidence: 99%

TrbB from Conjugative Plasmid F Is a Structurally Distinct Disulfide Isomerase That Requires DsbD for Redox State Maintenance

et al. 2011

View full text Add to dashboard Cite

show abstract

“…The experimental results from disulfidebond isomerase (DsbC) from E. coli (Banaszak et al, 2004;McCarthy et al, 2000) and Haemophilus influenza (Zhang et al, 2004) crystal structures, suggest hinge-flexibility within the proteins, which allows movements of the active sites, in order to accommodate the substrate in the cleft between the catalytic domains, and also differences in the orientation of the catalytic domains (Banaszak et al, 2004;McCarthy et al, 2000). This flexibility, essentially due to the x-linker region between b 0 and a 0 domains, agrees with the experimental data (Nguyen et al, 2008;Wang et al, 2010) and is fundamental for interaction with folding substrates.…”

Section: Analysis Of Catalytic Domainsmentioning

confidence: 99%

Besnoitia besnoiti protein disulfide isomerase (BbPDI): Molecular characterization, expression and in silico modelling

Marcelino

Martins

Morais

et al. 2011

Experimental Parasitology

View full text Add to dashboard Cite

a b s t r a c tBesnoitia besnoiti is an apicomplexan parasite responsible for bovine besnoitiosis, a disease with a high prevalence in tropical and subtropical regions and re-emerging in Europe. Despite the great economical losses associated with besnoitiosis, this disease has been underestimated and poorly studied, and neither an effective therapy nor an efficacious vaccine is available. Protein disulfide isomerase (PDI) is an essential enzyme for the acquisition of the correct three-dimensional structure of proteins. Current evidence suggests that in Neospora caninum and Toxoplasma gondii, which are closely related to B. besnoiti, PDI play an important role in host cell invasion, is a relevant target for the host immune response, and represents a promising drug target and/or vaccine candidate. In this work, we present the nucleotide sequence of the B. besnoiti PDI gene. BbPDI belongs to the thioredoxin-like superfamily (cluster 00388) and is included in the PDI_a family (cluster defined cd02961) and the PDI_a_PDI_a 0 _c subfamily (cd02995). A 3D theoretical model was built by comparative homology using Swiss-Model server, using as a template the crystallographic deduced model of Tapasin-ERp57 (PDB code 3F8U chain C). Analysis of the phylogenetic tree for PDI within the phylum apicomplexa reinforces the close relationship among B. besnoiti, N. caninum and T. gondii. When subjected to a PDI-assay based on the polymerisation of reduced insulin, recombinant BbPDI expressed in E. coli exhibited enzymatic activity, which was inhibited by bacitracin. Antiserum directed against recombinant BbPDI reacted with PDI in Western blots and by immunofluorescence with B. besnoiti tachyzoites and bradyzoites.

show abstract

“…Dimerization results in the formation of a V-shaped binding pocket lined with hydrophobic and uncharged residues (Figure 3) (Banaszak 2004, McCarthy 2000). DsbC is thought to recognize misfolded protein substrates through exposed hydrophobic patches on the protein surface (Darby 1998).…”

Section: Introductionmentioning

confidence: 99%

Thioredoxin-like proteins in F and other plasmid systems

Hemmis

Schildbach

2013

Plasmid

View full text Add to dashboard Cite

Bacterial conjugation is the process by which a conjugative plasmid transfers from donor to recipient bacterium. During this process, single-stranded plasmid DNA is actively and specifically transported from the cytoplasm of the donor, through a large membrane-spanning assembly known as the pore complex, and into the cytoplasm of the recipient. In Gram negative bacteria, construction of the pore requires localization of a subset of structural and catalytically active proteins to the bacterial periplasm. Unlike the cytoplasm, the periplasm contains proteins that promote disulfide bond formation within or between cysteine-containing proteins. To ensure proper protein folding and assembly, bacteria employ periplasmic redox systems for thiol oxidation, disulfide bond/sulfenic acid reduction, and disulfide bond isomerization. Recent data suggest that plasmid-based proteins belonging to the disulfide bond formation family play an integral role in the conjugative process by serving as mediators in folding and/or assembly of pore complex proteins. Here we report the identification of 165 thioredoxin-like family members across 89 different plasmid systems. Using phylogenetic analysis, all but nine family members were categorized into thioredoxin-like subfamilies. In addition, we discuss the diversity, conservation, and putative roles of thioredoxin-like proteins in plasmid systems, which include homologs of DsbA, DsbB, DsbC, DsbD, DsbG, and CcmG from Escherichia coli, TlpA from Bradyrhizobium japonicum, Com1 from Coxiella burnetii, as well as TrbB and TraF from plasmid F, and the absolute conservation of a disulfide isomerase in plasmids containing homologs of the transfer proteins TraH, TraN, and TraU.

show abstract

Structure of the reduced disulfide-bond isomerase DsbC fromEscherichia coli

Cited by 24 publications

References 11 publications

TrbB from Conjugative Plasmid F Is a Structurally Distinct Disulfide Isomerase That Requires DsbD for Redox State Maintenance

TrbB from Conjugative Plasmid F Is a Structurally Distinct Disulfide Isomerase That Requires DsbD for Redox State Maintenance

Besnoitia besnoiti protein disulfide isomerase (BbPDI): Molecular characterization, expression and in silico modelling

Thioredoxin-like proteins in F and other plasmid systems

Contact Info

Product

Resources

About