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86  structures 392  species 3  interactions 2322  sequences 26  architectures

Clan: Cystatin (CL0121)

Summary

Cystatin-like superfamily Add an annotation

This superfamily includes cystatins and cathelicidins [1]. The cystatin superfamily comprises cysteine protease inhibitors that play key regulatory roles in protein degradation processes. The progenitor of this superfamily was most probably intracellular and lacked a signal peptide and disulfide bridges, much like the extant Giardia cystatin. A primordial gene duplication produced two ancestral eukaryotic lineages, cystatins and stefins. Stefins - included in Pfam:PF00031 - remain encoded by a single or a small number of genes throughout the eukaryotes, whereas the cystatins have undergone a more complex and dynamic evolution through numerous gene and domain duplications [2].

This clan contains 4 families and the total number of domains in the clan is 2322. The clan was built by A Bateman.

Literature references

  1. Murzin AG; , J Mol Biol 1993;230:689-694.: Sweet-tasting protein monellin is related to the cystatin family of thiol proteinase inhibitors. PUBMED:8464079 EPMC:8464079
  2. Kordis D, Turk V;, BMC Evol Biol. 2009;9:266.: Phylogenomic analysis of the cystatin superfamily in eukaryotes and prokaryotes. PUBMED:19919722 EPMC:19919722

Members

This clan contains the following 4 member families:

Cathelicidins Cystatin PP1 Spp-24

External database links

Domain organisation

Below is a listing of the unique domain organisations or architectures from this clan. More...

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Alignments

The table below shows the number of occurrences of each domain throughout the sequence database. More...

Pfam family Num. domains Alignment
Cystatin (PF00031) 2054 (88.5%) View
Cathelicidins (PF00666) 193 (8.3%) View
Spp-24 (PF07448) 49 (2.1%) View
PP1 (PF07430) 26 (1.1%) View
Total: 4 Total: 2322 Clan alignment
 

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Family relationships

This diagram shows the relationships between members of this clan. More...

Species distribution

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This tree shows the occurrence of the domains in this clan across different species. More...

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Interactions

There are 3 interactions for this clan. More...

Interacting families
A B
Cystatin Cystatin
Peptidase_C1
Cathelicidins Cathelicidins

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 three-dimensional structures. The table below shows the mapping between the Pfam families in this clan, the corresponding UniProt entries, and the region of the three-dimensional structures that are available for that sequence.

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