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.
21  structures 360  species 4  interactions 2544  sequences 170  architectures

Family: U-box (PF04564)

Summary: U-box domain

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

The Pfam group coordinates the annotation of Pfam families in Wikipedia, but we have not yet assigned a Wikipedia article to this family. If you think that a particular Wikipedia article provides good annotation, please let us know.

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.

U-box domain Provide feedback

This domain is related to the Ring finger PF00097 but lacks the zinc binding residues [1].

Literature references

  1. Aravind L, Koonin EV; , Curr Biol 2000;10:132-134.: The U box is a modified RING finger - a common domain in ubiquitination. PUBMED:10704423 EPMC:10704423


External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR003613

Quality control of intracellular proteins is essential for cellular homeostasis. Molecular chaperones recognise and contribute to the refolding of misfolded or unfolded proteins, whereas the ubiquitin-proteasome system mediates the degradation of such abnormal proteins. Ubiquitin-protein ligases (E3s) determine the substrate specificity for ubiquitylation and have been classified into HECT and RING-finger families. More recently, however, U-box proteins, which contain a domain (the U box) of about 70 amino acids that is conserved from yeast to humans, have been identified as a new type of E3 [PUBMED:12944364].

Members of the U-box family of proteins constitute a class of ubiquitin-protein ligases (E3s) distinct from the HECT-type and RING finger-containing E3 families [PUBMED:12944364]. Using yeast two-hybrid technology, all mammalian U-box proteins have been reported to interact with molecular chaperones or co-chaperones, including Hsp90, Hsp70, DnaJc7, EKN1, CRN, and VCP. This suggests that the function of U box-type E3s is to mediate the degradation of unfolded or misfolded proteins in conjunction with molecular chaperones as receptors that recognise such abnormal proteins [PUBMED:15115282, PUBMED:15189447].

Unlike the RING finger domain, INTERPRO, that is stabilised by Zn2+ ions coordinated by the cysteines and a histidine, the U-box scaffold is probably stabilised by a system of salt-bridges and hydrogen bonds. The charged and polar residues that participate in this network of bonds are more strongly conserved in the U-box proteins than in classic RING fingers, which supports their role in maintaining the stability of the U box. Thus, the U box appears to have evolved from a RING finger domain by appropriation of a new set of residues required to stabilise its structure, concomitant with the loss of the original, metal-chelating residues [PUBMED:10704423].

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...

Loading domain graphics...

Pfam Clan

This family is a member of clan RING (CL0229), which has the following description:

This clan includes the Ring zinc finger domains as well as the U-box domain that appears to have lost the zinc coordinating cysteine residues [1].

The clan contains the following 24 members:

Baculo_RING FANCL_C Prok-RING_1 Prok-RING_2 Prok-RING_4 RINGv Rtf2 U-box zf-Apc11 zf-C3HC4 zf-C3HC4_2 zf-C3HC4_3 zf-C3HC4_4 zf-MIZ zf-Nse zf-rbx1 zf-RING-like zf-RING_2 zf-RING_4 zf-RING_5 zf-RING_6 zf-RING_UBOX zf-UBP zf-UDP

Alignments

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 using the family HMM. We also generate alignments using four representative proteomes (RP) sets, 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.

  Seed
(16)
Full
(2544)
Representative proteomes NCBI
(2959)
Meta
(196)
RP15
(505)
RP35
(1047)
RP55
(1434)
RP75
(1743)
Jalview View  View  View  View  View  View  View  View 
HTML View  View  View  View  View  View     
PP/heatmap 1 View  View  View  View  View     
Pfam viewer View  View             

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

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

Format an alignment

  Seed
(16)
Full
(2544)
Representative proteomes NCBI
(2959)
Meta
(196)
RP15
(505)
RP35
(1047)
RP55
(1434)
RP75
(1743)
Alignment:
Format:
Order:
Sequence:
Gaps:
Download/view:

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.

  Seed
(16)
Full
(2544)
Representative proteomes NCBI
(2959)
Meta
(196)
RP15
(505)
RP35
(1047)
RP55
(1434)
RP75
(1743)
Raw Stockholm Download   Download   Download   Download   Download   Download   Download   Download  
Gzipped 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.

External links

MyHits provides a collection of tools to handle multiple sequence alignments. For example, one can refine a seed alignment (sequence addition or removal, re-alignment or manual edition) and then search databases for remote homologs using HMMER3.

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...

Trees

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: Pfam-B_2801 (release 7.5)
Previous IDs: none
Type: Domain
Author: Bateman A
Number in seed: 16
Number in full: 2544
Average length of the domain: 70.60 aa
Average identity of full alignment: 32 %
Average coverage of the sequence by the domain: 11.07 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 21.4 21.4
Trusted cut-off 21.4 21.4
Noise cut-off 21.3 21.3
Model length: 73
Family (HMM) version: 10
Download: download the raw HMM for this family

Species distribution

Sunburst controls

Show

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

Hide

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

Loading...

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.

Interactions

There are 4 interactions for this family. More...

Ufd2P_core UQ_con U-box TPR_1

Structures

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 U-box domain has been found. There are 21 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 seqence.

Loading structure mapping...