Summary
Ulp1 protease family, C-terminal catalytic domain
This domain contains the catalytic triad Cys-His-Asn.
Literature references
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Mossessova E, Lima CD; , Mol Cell 2000;5:865-876.: Ulp1-SUMO crystal structure and genetic analysis reveal conserved interactions and a regulatory element essential for cell growth in yeast. PUBMED:10882122
InterPro entry IPR003653
In the MEROPS database peptidases and peptidase homologues are grouped into clans and families. Clans are groups of families for which there is evidence of common ancestry based on a common structural fold:
- Each clan is identified with two letters, the first representing the catalytic type of the families included in the clan (with the letter 'P' being used for a clan containing families of more than one of the catalytic types serine, threonine and cysteine). Some families cannot yet be assigned to clans, and when a formal assignment is required, such a family is described as belonging to clan A-, C-, M-, S-, T- or U-, according to the catalytic type. Some clans are divided into subclans because there is evidence of a very ancient divergence within the clan, for example MA(E), the gluzincins, and MA(M), the metzincins.
- Peptidase families are grouped by their catalytic type, the first character representing the catalytic type: A, aspartic; C, cysteine; G, glutamic acid; M, metallo; S, serine; T, threonine; and U, unknown. The serine, threonine and cysteine peptidases utilise the amino acid as a nucleophile and form an acyl intermediate - these peptidases can also readily act as transferases. In the case of aspartic, glutamic and metallopeptidases, the nucleophile is an activated water molecule.
In many instances the structural protein fold that characterises the clan or family may have lost its catalytic activity, yet retain its function in protein recognition and binding.
Cysteine peptidases have characteristic molecular topologies, which can be seen not only in their three-dimensional structures, but commonly also in the two-dimensional structures. These are peptidases in which the nucleophile is the sulphydryl group of a cysteine residue. Cysteine proteases are divided into clans (proteins which are evolutionary related), and further sub-divided into families, on the basis of the architecture of their catalytic dyad or triad PUBMED:11517925.
This group of proteins contain cysteine peptidases belonging to MEROPS peptidase family C48 (Ulp1 endopeptidase family, clan CE). The protein fold of the peptidase domain for members of this family resembles that of adenain, the type example for clan CE. This group of sequences also contains a number of hypothetical proteins, which have not yet been characterised, and non-peptidase homologues. These are proteins that have either been found experimentally to be without peptidase activity, or lack amino acid residues that are believed to be essential for the catalytic activity of the peptidases in the family.
The Ulp1 endopeptidase family contain the deubiquitinating enzymes (DUB) that can de-conjugate ubiquitin or ubiquitin-like proteins from ubiquitin-conjugated proteins. They can be classified in 3 families according to sequence homology PUBMED:10603300, PUBMED:8982460: Ubiquitin carboxyl-terminal hydrolase (UCH) (see ), Ubiquitin-specific processing protease (UBP) (see ), and ubiquitin-like protease (ULP) specific for de-conjugating ubiquitin-like proteins. In contrast to the UBP pathway, which is very redundant (16 UBP enzymes in yeast), there are few ubiquitin-like proteases (only one in yeast, Ulp1).
Ulp1 catalyses two critical functions in the SUMO/Smt3 pathway via its cysteine protease activity. Ulp1 processes the Smt3 C-terminal sequence (-GGATY) to its mature form (-GG), and it de-conjugates Smt3 from the lysine epsilon-amino group of the target protein PUBMED:10094048.
Crystal structure of yeast Ulp1 bound to Smt3 PUBMED:10882122 revealed that the catalytic and interaction interface is situated in a shallow and narrow cleft where conserved residues recognise the Gly-Gly motif at the C-terminal extremity of Smt3 protein. Ulp1 adopts a novel architecture despite some structural similarity with other cysteine protease. The secondary structure is composed of seven alpha helices and seven beta strands. The catalytic domain includes the central alpha helix, beta-strands 4 to 6, and the catalytic triad (Cys-His-Asp). This profile is directed against the C-terminal part of ULP proteins that displays full proteolytic activity PUBMED:10882122.
Clan
This family is a member of clan Peptidase_CE (CL0134), which contains the following 3 members:
Peptidase_C48 Peptidase_C5 YopJGene Ontology
| Molecular function | cysteine-type peptidase activity (GO:0008234) |
| Biological process | proteolysis (GO:0006508) |
External database links
| MEROPS: | C48 |
| PANDIT: | PF02902 |
| SCOP: | 1euv |
| SYSTERS: | Peptidase_C48 |
Domain organisation
Below is a listing of the unique domain organisations or architectures in which this domain is found. More...
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Alignments
There are various ways to view or download the sequence alignments that we store. You can use a sequence viewer to look at either the seed or full alignment for the family, or you can look at a plain text version of the sequence in a variety of different formats. More...
View options
Formatting options
Download options
Very large alignments can often cause problems for the formatting tool above. If you find that downloading or viewing a large alignment is problematic, you can also download a gzip-compressed, Stockholm-format file containing the seed or full alignment for this family.
You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.
The main seed and full alignments are generated using sequences from the UniProt sequence database. However, we also generate alignments using sequences from the NCBI sequence database and the "metaseq" metagenomics dataset.
You can view alignments from these two additional datasets using the form above, or you can download alignments of NCBI or metagenomics sequences, as gzip-compressed files.
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 HMMER2.
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. 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 or full alignments.
Note: You can also download the data files for the seed, full, NCBI or metagenomics trees.
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
| Seed source: | Structural domain |
| Previous IDs: | Ulp1_C; |
| Type: | Domain |
| Author: | Griffiths-Jones SR |
| Number in seed: | 27 |
| Number in full: | 1417 |
| Average length of the domain: | 168.40 aa |
| Average identity of full alignment: | 16 % |
| Average coverage of the sequence by the domain: | 23.96 % |
HMM information
| HMM build commands: |
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 9421015 -E 1000 HMM pfamseq
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| Model details: |
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| Model length: | 216 | ||||||||||||
| Family (HMM) version: | 12 | ||||||||||||
| Download: | download the raw HMM for this family |
Species distribution
Tree controls
HideThe tree shows the occurrence of this domain across different species. More...
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Interactions
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 MSD 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 Peptidase_C48 domain has been found.
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