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50  structures 1493  species 0  interactions 9387  sequences 333  architectures

Family: Motile_Sperm (PF00635)

Summary: MSP (Major sperm protein) domain

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MSP (Major sperm protein) domain Provide feedback

Major sperm proteins are involved in sperm motility. These proteins oligomerise to form filaments. This family contains many other proteins.

Literature references

  1. Bullock TL, Roberts TM, Stewart M; , J Mol Biol 1996;263:284-296.: 2.5 A resolution crystal structure of the motile major sperm protein (MSP) of Ascaris suum. PUBMED:8913307 EPMC:8913307

  2. King KL, Stewart M, Roberts TM, Seavy M; , J Cell Sci 1992;101:847-857.: Structure and macromolecular assembly of two isoforms of the major sperm protein (MSP) from the amoeboid sperm of the nematode, Ascaris suum. PUBMED:1527183 EPMC:1527183

Internal database links

External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR000535

Nematode sperm are unusual amoeboid cells in which motility is not based on actin, but instead on the major sperm protein (MSP). MSP is a dimeric molecule that polymerises to form non-polar filaments constructed from two helical subfilaments that wind round one another. The filaments then assemble into larger macromolecular assemblies called fibre complexes. MSP is a small (~14kDa) basic protein typically encoded by a multigene family of up to 28 members [ PUBMED:8913307 , PUBMED:12051923 , PUBMED:9878374 , PUBMED:9641981 ]. An about 120-amino acid domain similar to MSP has been found in other proteins, including:

  • Animal Vesicle-Associated Membrane Protein-associated (VAMP-associated) protein family of 33kDa (VAP33). VAP33 is required for neurotransmitter release. It binds to the v-SNARE synaptobrevin/VAMP which is associated with vesicle fusion. VAP33 has a two-domain structure with its N terminus being highly homologous to MSP, whereas its C terminus is based on a putative alpha-helical coiled-coil combined with an extremely hydrophobic membrane-attachment region [ PUBMED:9920726 ].
  • Nicotiana plumbaginifolia VAP27, a VAP33 homologue. It interacts with the resistance protein Cf9 [ PUBMED:10733941 ].
  • Yeast inositol regulator SCS2, a VAP33 homologue. It is C-terminally anchored to the endoplasmic reticulum [ PUBMED:9537365 ].

The MSP polypeptide chain has an immunoglobulin-like fold based on a seven-stranded beta sandwich measuring approximately 15 A x 20 A x 45 A and having opposing three-stranded and four-stranded beta sheets [ PUBMED:8913307 ].

This entry represents the MSP domain.

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 PapD-like (CL0556), which has the following description:

This superfamily is characterised by proteins in families involved in ciliary or flagellar function. The families may be acting as chaperones.

The clan contains the following 8 members:

ASH DUF1573 EcpB_C Motile_Sperm PapD-like PapD_N Peptidase_M60_C TMEM131_like_N


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

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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.

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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: MSP_domain;
Type: Domain
Sequence Ontology: SO:0000417
Author: Bateman A , Griffiths-Jones SR
Number in seed: 50
Number in full: 9387
Average length of the domain: 103.20 aa
Average identity of full alignment: 24 %
Average coverage of the sequence by the domain: 33.05 %

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 25.9 25.9
Trusted cut-off 25.9 25.9
Noise cut-off 25.8 25.8
Model length: 109
Family (HMM) version: 29
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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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 Motile_Sperm domain has been found. There are 50 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
A0A0G2K8D1 View 3D Structure Click here
A0A0P0VMG3 View 3D Structure Click here
A0A0P0VMK0 View 3D Structure Click here
A0A0P0Y121 View 3D Structure Click here
A0A0R0EF48 View 3D Structure Click here
A0A0R0GTI5 View 3D Structure Click here
A0A0R0H3L7 View 3D Structure Click here
A0A0R0HUB4 View 3D Structure Click here
A0A1D6FRH7 View 3D Structure Click here
A0A1D6G8Z4 View 3D Structure Click here
A0A1D6GRB5 View 3D Structure Click here
A0A1D6GZQ0 View 3D Structure Click here
A0A1D6H673 View 3D Structure Click here
A0A1D6HEK8 View 3D Structure Click here
A0A1D6HEU8 View 3D Structure Click here
A0A1D6HF60 View 3D Structure Click here
A0A1D6JAZ6 View 3D Structure Click here
A0A1D6KR67 View 3D Structure Click here
A0A1D6LLW8 View 3D Structure Click here
A0A1D6N1Z3 View 3D Structure Click here
A0A1D6PN23 View 3D Structure Click here
A0A1D6PYD0 View 3D Structure Click here
A0A1D6Q6A5 View 3D Structure Click here
A0A1D8PQC2 View 3D Structure Click here
A0A2R8QKX7 View 3D Structure Click here
A0A368UK56 View 3D Structure Click here
A4HU27 View 3D Structure Click here
A4HXJ8 View 3D Structure Click here
A8WGM1 View 3D Structure Click here
B4F9V2 View 3D Structure Click here
B4FUC2 View 3D Structure Click here
B6SWZ3 View 3D Structure Click here
B6TP74 View 3D Structure Click here
B7FA48 View 3D Structure Click here
B9DHD7 View 3D Structure Click here
C0HGS1 View 3D Structure Click here
C0P9G0 View 3D Structure Click here
C4JB68 View 3D Structure Click here
C6T767 View 3D Structure Click here
C6T8H2 View 3D Structure Click here