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681  structures 8786  species 0  interactions 47055  sequences 532  architectures

Family: FKBP_C (PF00254)

Summary: FKBP-type peptidyl-prolyl cis-trans isomerase

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 "FKBP". More...

FKBP Edit Wikipedia article

FKBP, or FK506 binding protein, is a family of proteins that have prolyl isomerase activity and are related to the cyclophilins in function, though not in amino acid sequence. FKBPs have been identified in many eukaryotes from yeast to humans and function as protein folding chaperones for proteins containing proline residues. Along with cyclophilin, FKBPs belong to the immunophilin family.[1]

FKBP12 is notable in humans for binding the immunosuppressant molecule tacrolimus (originally designated FK506), which is used in treating patients after organ transplant and patients suffering from autoimmune disorders. Tacrolimus has been found to reduce episodes of organ rejection over a related treatment, the drug ciclosporin, which binds cyclophilin.[2] Both the FBKP-tacrolimus complex and the ciclosporin-cyclophilin complex inhibit a phosphatase called calcineurin, thus blocking signal transduction in the T-lymphocyte transduction pathway.[3] This therapeutic role is not related to prolyl isomerase activity.

External links


  1. ^ Balbach J, Schmid FX. (2000). Proline isomerizarion and its catalysis in protein folding. In Mechanisms of Protein Folding 2nd ed. Ed. RH Pain. Frontiers in Molecular Biology series. Oxford University Press: Oxford, UK.
  2. ^ Mayer DA et al. (1997). MULTICENTER RANDOMIZED TRIAL COMPARING TACROLIMUS (FK506) AND CYCLOSPORINE IN THE PREVENTION OF RENAL ALLOGRAFT REJECTION 1: A Report of the European Tacrolimus Multicenter Renal Study Group. Transplantation. 64(3):436-443.
  3. ^ Liu J, Farmer J, Lane W, Friedman J, Weissman I, Schreiber S. (1991). Calcineurin is a common target of cyclophilin-cyclosporin A and FKBP-FK506 complexes. Cell 66 (4): 807-15.

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.

FKBP-type peptidyl-prolyl cis-trans isomerase Provide feedback

No Pfam abstract.

Internal database links

External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR001179

FKBP-type peptidylprolyl isomerases ( EC ) in vertebrates, are receptors for the two immunosuppressants, FK506 and rapamycin. The drugs inhibit T cell proliferation by arresting two distinct cytoplasmic signal transmission pathways. Peptidylprolyl isomerases accelerate protein folding by catalysing the cis-trans isomerisation of proline imidic peptide bonds in oligopeptides. These proteins are found in a variety of organisms [ PUBMED:27664121 ].

This entry represents a domain found in FKBP-type peptidylprolyl isomerases.

Gene Ontology

The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.

Domain organisation

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

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Pfam Clan

This family is a member of clan FKBP (CL0487), which has the following description:

This superfamily includes the FKBP domain which catalyses the peptidyl-prolyl cis-trans isomerisation reaction. The superfamily also includes the C-terminal domain of GreA and the c-terminal dmoain of 3-mercaptopyruvate sulfurtransferase.

The clan contains the following 11 members:

DUF1930 DUF4827 FKBP26_C FKBP_C FKBP_N_2 GCD14_N GreA_GreB OSR1_C Rotamase Rotamase_2 Rotamase_3


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 and the UniProtKB sequence database. More...

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

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

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Representative proteomes UniProt

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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.

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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: Prosite
Previous IDs: FKBP;
Type: Domain
Sequence Ontology: SO:0000417
Author: Finn RD
Number in seed: 131
Number in full: 47055
Average length of the domain: 96.8 aa
Average identity of full alignment: 27 %
Average coverage of the sequence by the domain: 37.05 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 61295632 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 21.1 21.1
Trusted cut-off 21.1 21.1
Noise cut-off 21.0 21.0
Model length: 94
Family (HMM) version: 31
Download: download the raw HMM for this family

Species distribution

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Colour assignments

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


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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...

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


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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 FKBP_C domain has been found. There are 681 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.

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AlphaFold Structure Predictions

The list of proteins below match this family and have AlphaFold predicted structures. Click on the protein accession to view the predicted structure.

Protein Predicted structure External Information
A0A044RW09 View 3D Structure Click here
A0A044RZQ4 View 3D Structure Click here
A0A044SPA6 View 3D Structure Click here
A0A044TBT0 View 3D Structure Click here
A0A044U3K9 View 3D Structure Click here
A0A044UH08 View 3D Structure Click here
A0A044V5Y3 View 3D Structure Click here
A0A077YZE2 View 3D Structure Click here
A0A077Z3W7 View 3D Structure Click here
A0A077Z4M8 View 3D Structure Click here
A0A077ZAC5 View 3D Structure Click here
A0A0B4K7C5 View 3D Structure Click here
A0A0D2DR38 View 3D Structure Click here
A0A0D2DTP8 View 3D Structure Click here
A0A0D2GTC2 View 3D Structure Click here
A0A0H3GI67 View 3D Structure Click here
A0A0H3GMC8 View 3D Structure Click here
A0A0H3GNC9 View 3D Structure Click here
A0A0H3GP17 View 3D Structure Click here
A0A0H3GU42 View 3D Structure Click here
A0A0H3GYC9 View 3D Structure Click here
A0A0K0DT25 View 3D Structure Click here
A0A0K0DVQ1 View 3D Structure Click here
A0A0K0DYD0 View 3D Structure Click here
A0A0K0E3I2 View 3D Structure Click here
A0A0K0E524 View 3D Structure Click here
A0A0K0E8H8 View 3D Structure Click here
A0A0K0ED07 View 3D Structure Click here
A0A0K0J3B8 View 3D Structure Click here
A0A0K0J7U9 View 3D Structure Click here
A0A0K0JTK3 View 3D Structure Click here
A0A0N4U744 View 3D Structure Click here
A0A0N4UD23 View 3D Structure Click here
A0A0N4UD25 View 3D Structure Click here
A0A0N4UL37 View 3D Structure Click here
A0A0N4UQ43 View 3D Structure Click here
A0A0N4UQ99 View 3D Structure Click here
A0A0N4URB3 View 3D Structure Click here
A0A0N7KQB9 View 3D Structure Click here
A0A0P0V444 View 3D Structure Click here