Please note: this site relies heavily on the use of javascript. Without a javascript-enabled browser, this site will not function correctly. Please enable javascript and reload the page, or switch to a different browser.
30  structures 1558  species 2  interactions 1933  sequences 6  architectures

Family: DsbC_N (PF10411)

Summary: Disulfide bond isomerase protein N-terminus

Pfam includes annotations and additional family information from a range of different sources. These sources can be accessed via the tabs below.

This is the Wikipedia entry entitled "DsbC protein family". More...

DsbC protein family Edit Wikipedia article

Disulfide bond isomerase protein N-terminus
PDB 1t3b EBI.jpg
X-ray structure of DsbC from Haemophilus influenzae
Symbol DsbC_N
Pfam PF10411
InterPro IPR018950

DsbC (Disulfide bond C) is a prokaryotic disulfide bond isomerase. The formation of native disulfide bonds play an important role in the proper folding of proteins and stabilize tertiary structures of the protein.[1][2][3] DsbC is one of 6 proteins in the Dsb family in prokaryotes. The other proteins are DsbA, DsbB, DsbD, DsbE and DsbG.[4] These enzymes work in tandem with each other to form disulfide bonds during the expression of proteins. DsbC and DsbG act as proofreaders of the disulfide bonds that are formed. They break non-native disulfide bonds that were formed and act as chaperones for the formation of native disulfide bonds.[5][6] The isomerization of disulfide bonds occurs in the periplasm.

Enzyme Mechanism

DsbA, DsbC and DsbG have a common Cys-Xxx-Xxx-Cys (Cys-Cysteine) motif in their active site, where Xxx can be any amino acid.[7] In the periplasm, DsbA oxidizes thiols in cysteines to form disulfide bonds in proteins. DsbA receives its oxidizing potential from the cytosol through DsbB.[6] However, the probability of forming a non-native disulfide bond increases with the number of cysteines in the protein sequence. This leads to improperly folded proteins.

DsbC and DsbG facilitate the proper folding of the protein by breaking non-native disulfide bonds. In addition to this, DsbC also shows chaperone activity.[1][3] The reduced cysteine on DsbC performs a nucleophilic attack on the target non-native disulfide bond, to form an unstable disulfide bond between DsbC and the protein. Another thiolate group in the protein then attacks this unstable bond. The final result would be the formation of a native disulfide bond and the reformation of the thiolate group in DsbC.[4][7][8] DsbG also acts with a similar mechanism, but has a higher selectivity when compared with DsbC.[9]

Both DsbC and DsbG receive their reducing power, through DsbD, from the cytosol.[6][10] DsbC and DsbG have been maintained in their reduced forms to ensure proper folding of proteins, with the formation of multiple disulfide bonds.[11]

Enzyme Structure

DsbC is a modular dimer, with two 23.3 kDa subunits. There are four cysteines in each monomer, with two present in the active site.

Modular dimer of DsbC. Each module shown in a different color. Generated from 1EEJ

The common motif is Cys98-Gly-Tyr-Cys101.[1][3][12] The fact that Cys 98 is partially solvent exposed supports the mechanism provided above.[12] DsbG has a sequence homology of 24% identity with DsbC, thus suggesting a similar structure with that of DsbC.[12]

The Cys98-Gly-Tyr-Cys101 chain in DsbC. Cys backbones are shown in green, with sulfur atoms colored yellow. Note that DsbC is in an oxidized state. Generated from 1EEJ

The structure of DsbC from E. coli as reported by McCarthy et al.[12] shows the cysteines in the oxidized state. In wild-type cells, both cysteines are in the reduced state.

Disease Relevance

Synthesis of proteins with multiple disulfide bonds is challenging due to formation of non-native disulfide bonds. This usually leads to insoluble, inactive proteins. Co-expressing DsbA and DsbC has shown to help express soluble proteins with even more than five disulfide bonds. Two examples of proteins with medical applications that were expressed using this approach are the expression of reteplase in E.Coli[4] and the functional expression of single chain Fv antibodies in E. Coli [1] Reteplase is used in the treatment of ischemic stroke and contains 9 disulfide bonds. Prior to co-expressing the protein with DsbA and DsbC, the soluble expression in vivo was very low due to improper disulfide bond formation. Protein obtained from this co-expression system was also reported to have 20 times the thrombolytic activity than previously reported.


  1. ^ a b c d Zhang Z, Li ZH, Wang F, Fang M, Yin CC, Zhou ZY, Lin Q, Huang HL (November 2002). "Overexpression of DsbC and DsbG markedly improves soluble and functional expression of single-chain Fv antibodies in Escherichia coli". Protein Expression and Purification. 26 (2): 218–28. doi:10.1016/S1046-5928(02)00502-8. PMID 12406675. 
  2. ^ Maskos K, Huber-Wunderlich M, Glockshuber R (January 2003). "DsbA and DsbC-catalyzed oxidative folding of proteins with complex disulfide bridge patterns in vitro and in vivo". Journal of Molecular Biology. 325 (3): 495–513. doi:10.1016/S0022-2836(02)01248-2. PMID 12498799. 
  3. ^ a b c Chen J, Song JL, Zhang S, Wang Y, Cui DF, Wang CC (July 1999). "Chaperone activity of DsbC". The Journal of Biological Chemistry. 274 (28): 19601–5. doi:10.1074/jbc.274.28.19601. PMID 10391895. 
  4. ^ a b c Zhuo XF, Zhang YY, Guan YX, Yao SJ (December 2014). "Co-expression of disulfide oxidoreductases DsbA/DsbC markedly enhanced soluble and functional expression of reteplase in Escherichia coli". Journal of Biotechnology. 192 Pt A: 197–203. doi:10.1016/j.jbiotec.2014.10.028. PMID 25449110. 
  5. ^ Nakamoto H, Bardwell JC (November 2004). "Catalysis of disulfide bond formation and isomerization in the Escherichia coli periplasm". Biochimica et Biophysica Acta. 1694 (1-3): 111–9. doi:10.1016/j.bbamcr.2004.02.012. PMID 15546661. 
  6. ^ a b c Kim JH, Kim SJ, Jeong DG, Son JH, Ryu SE (May 2003). "Crystal structure of DsbDgamma reveals the mechanism of redox potential shift and substrate specificity(1)". FEBS Letters. 543 (1-3): 164–9. doi:10.1016/S0014-5793(03)00434-4. PMID 12753926. 
  7. ^ a b Jiao L, Kim JS, Song WS, Yoon BY, Lee K, Ha NC (July 2013). "Crystal structure of the periplasmic disulfide-bond isomerase DsbC from Salmonella enterica serovar Typhimurium and the mechanistic implications". Journal of Structural Biology. 183 (1): 1–10. doi:10.1016/j.jsb.2013.05.013. PMID 23726983. 
  8. ^ Messens J, Collet JF (January 2006). "Pathways of disulfide bond formation in Escherichia coli". The International Journal of Biochemistry & Cell Biology. 38 (7): 1050–62. doi:10.1016/j.biocel.2005.12.011. PMID 16446111. 
  9. ^ Andersen CL, Matthey-Dupraz A, Missiakas D, Raina S (October 1997). "A new Escherichia coli gene, dsbG, encodes a periplasmic protein involved in disulphide bond formation, required for recycling DsbA/DsbB and DsbC redox proteins". Molecular Microbiology. 26 (1): 121–32. doi:10.1046/j.1365-2958.1997.5581925.x. PMID 9383195. 
  10. ^ Joly JC, Swartz JR (August 1997). "In vitro and in vivo redox states of the Escherichia coli periplasmic oxidoreductases DsbA and DsbC". Biochemistry. 36 (33): 10067–72. doi:10.1021/bi9707739. PMID 9254601. 
  11. ^ Rietsch A, Bessette P, Georgiou G, Beckwith J (November 1997). "Reduction of the periplasmic disulfide bond isomerase, DsbC, occurs by passage of electrons from cytoplasmic thioredoxin". Journal of Bacteriology. 179 (21): 6602–8. doi:10.1128/jb.179.21.6602-6608.1997. PMC 179585Freely accessible. PMID 9352906. 
  12. ^ a b c d McCarthy AA, Haebel PW, Törrönen A, Rybin V, Baker EN, Metcalf P (March 2000). "Crystal structure of the protein disulfide bond isomerase, DsbC, from Escherichia coli". Nature Structural Biology. 7 (3): 196–9. doi:10.1038/73295. PMID 10700276. 

This article incorporates text from the public domain Pfam and InterPro IPR018950

This page is based on a Wikipedia article. The text is available under the Creative Commons Attribution/Share-Alike License.

This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.

Disulfide bond isomerase protein N-terminus Provide feedback

This is the N-terminal domain of the disulfide bond isomerase DsbC. The whole molecule is V-shaped, where each arm is a DsbC monomer of two domains linked by a hinge; and the N-termini of each monomer join to form the dimer interface at the base of the V, so are vital for dimerisation [1]. DsbC is required for disulfide bond formation and functions as a disulfide bond isomerase during oxidative protein-folding in bacterial periplasm. It also has chaperone activity [2].

Literature references

  1. McCarthy AA, Haebel PW, Torronen A, Rybin V, Baker EN, Metcalf P; , Nat Struct Biol. 2000;7:196-199.: Crystal structure of the protein disulfide bond isomerase, DsbC, from Escherichia coli. PUBMED:10700276 EPMC:10700276

  2. Hiniker A, Collet JF, Bardwell JC; , J Biol Chem. 2005;280:33785-33791.: Copper stress causes an in vivo requirement for the Escherichia coli disulfide isomerase DsbC. PUBMED:16087673 EPMC:16087673

This tab holds annotation information from the InterPro database.

InterPro entry IPR018950

This is the N-terminal domain of the disulphide bond isomerase DsbC and DsbG.

The whole molecule is V-shaped, where each arm is a DsbC monomer of two domains linked by a hinge; and the N-termini of each monomer join to form the dimer interface at the base of the V, so are vital for dimerisation [PUBMED:10700276]. DsbC is required for disulphide bond formation and functions as a disulphide bond isomerase during oxidative protein-folding in bacterial periplasm. It also has chaperone activity [PUBMED:16087673].

Domain organisation

Below is a listing of the unique domain organisations or architectures in which this domain is found. More...

Loading domain graphics...


We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database (reference proteomes) using the family HMM. We also generate alignments using four representative proteomes (RP) sets, the UniProtKB sequence database, the NCBI sequence database, and our metagenomics sequence database. More...

View options

We make a range of alignments for each Pfam-A family. You can see a description of each above. You can view these alignments in various ways but please note that some types of alignment are never generated while others may not be available for all families, most commonly because the alignments are too large to handle.

Representative proteomes UniProt
Jalview View  View  View  View  View  View  View  View  View 
HTML View  View               
PP/heatmap 1 View               

1Cannot generate PP/Heatmap alignments for seeds; no PP data available

Key: ✓ available, x not generated, not available.

Format an alignment

Representative proteomes UniProt

Download options

We make all of our alignments available in Stockholm format. You can download them here as raw, plain text files or as gzip-compressed files.

Representative proteomes UniProt
Raw Stockholm Download   Download   Download   Download   Download   Download   Download   Download   Download  
Gzipped Download   Download   Download   Download   Download   Download   Download   Download   Download  

You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.

HMM logo

HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...


This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.

Note: You can also download the data file for the tree.

Curation and family details

This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.

Curation View help on the curation process

Seed source: Gene3D, pdb_1eej
Previous IDs: none
Type: Domain
Sequence Ontology: SO:0000417
Author: Finn RD , Coggill P
Number in seed: 185
Number in full: 1933
Average length of the domain: 54.00 aa
Average identity of full alignment: 26 %
Average coverage of the sequence by the domain: 21.52 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 45638612 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 21.0 21.0
Trusted cut-off 21.0 21.0
Noise cut-off 20.9 20.8
Model length: 54
Family (HMM) version: 9
Download: download the raw HMM for this family

Species distribution

Sunburst controls


Weight segments by...

Change the size of the sunburst


Colour assignments

Archea Archea Eukaryota Eukaryota
Bacteria Bacteria Other sequences Other sequences
Viruses Viruses Unclassified Unclassified
Viroids Viroids Unclassified sequence Unclassified sequence


Align selected sequences to HMM

Generate a FASTA-format file

Clear selection

This visualisation provides a simple graphical representation of the distribution of this family across species. You can find the original interactive tree in the adjacent tab. More...

Loading sunburst data...

Tree controls


The tree shows the occurrence of this domain across different species. More...


Please note: for large trees this can take some time. While the tree is loading, you can safely switch away from this tab but if you browse away from the family page entirely, the tree will not be loaded.


There are 2 interactions for this family. More...

Thioredoxin_2 DsbC_N


For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the DsbC_N domain has been found. There are 30 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein sequence.

Loading structure mapping...