s48_45Sexual stage antigen s48/45 domain
|SMART accession number:||SM00970|
|Description:||This family contains sexual stage s48/45 antigens from Plasmodium (approximately 450 residues long). These are surface proteins expressed by Plasmodium male and female gametes that have been shown to play a conserved and important role in fertilisation (PUBMED:11163248).|
|Interpro abstract (IPR010884):|
This entry represents the 6-Cys domain.
The 6-Cysteine (6-Cys) domain is found in Plasmodium proteins that are expressed in all stages of the parasite life cycle in both the vertebrate and mosquito hosts. The domain is of roughly 120 amino acids and contains six positionally conserved cysteines. It might occur in 1-14 copies per protein, either as the sole globular domain or in combination wih beta-helix-forming hexapeptide repeats as is the case of sequestrin. It is generally found in tandem pairs of A-type and B-type domains. Previously believed to be exclusive to Plasmodium, the 6-Cys domain also exists in proteins found in all members of the aconoidasidan (hematozoan) clade of Apicomplexa, which unites the haemosporidians (Plasmodium) and piroplasms) [(PUBMED:11163248), (PUBMED:16155126), (PUBMED:20386715), (PUBMED:22493233), (PUBMED:23511632)].
The 6-cys domain is a beta-sandwich formed by two sheets with a mixture of parallel and antiparallel strands. Three disulfide bonds are present in the 6_Cys domain with C1-C2, C3-C6, and C4-C5 connectivity. C1-C2 and C3-C6 pin together the two sheets of the beta-sandwich, whereas C4-C5 links an ancyllary loop to the core domain [(PUBMED:22493233), (PUBMED:23511632)].
Some Plasmodium proteins known to contain a 6-Cys domain are listed below:
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- Evolution (species in which this domain is found)
- Cellular role (predicted cellular role)
- Literature (relevant references for this domain)
- Structure (3D structures containing this domain)
- Links (links to other resources describing this domain)