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225  structures 1554  species 0  interactions 59721  sequences 1283  architectures

Clan: WW (CL0680)


WW domain Add an annotation

The WW domain is composed of 38 to 40 semi-conserved amino acids. They are found in many human proteins and play integral roles in systems connected to the appearance of Alzheimer’s, Huntington’s, muscular dystrophy, and cancer. In particular, loss-of-function mutations that disrupt WW domain–ligand interactions can lead to major complications. WW domains fold into a three-stranded beta sheet that binds polyproline motifs. They have been divided into four main classes, corresponding to the polyproline motif with which they interact: class 1 with PPxY motifs, class 2 with PPPL/R motifs, class 3 with (PxxGMxPP)*2 motifs, and class 4 with (pS/pT)P motifs (p=phosphorylation) [1].

This clan contains 2 families and the total number of domains in the clan is 59721. The clan was built by S El-Gebali.

Literature references

  1. Dodson EJ, Fishbain-Yoskovitz V, Rotem-Bamberger S, Schueler-Furman O;, Exp Biol Med (Maywood). 2015;240:351-360.: Versatile communication strategies among tandem WW domain repeats. PUBMED:25710931 EPMC:25710931


This clan contains the following 2 member families:


Domain organisation

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

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

Pfam family Num. domains Alignment
WW (PF00397) 59696 (100.0%) View
WW_1 (PF18507) 25 (0.0%) View
Total: 2 Total: 59721 Clan alignment

Please note: Clan alignments can be very large and can cause problems for some browsers. Read the note above before viewing.

Family relationships

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

Species distribution

Tree controls


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



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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