| Primary Identifier | IPR010884 | Type | Domain |
| Short Name | 6_CYS_dom |
| description | This entry represents the 6-Cys domain.The 6-Cysteine (6-Cys) domain is found in Plasmodium proteins that areexpressed in all stages of the parasite life cycle in both the vertebrate andmosquito hosts. The domain is of roughly 120 amino acids and contains sixpositionally conserved cysteines. It might occur in 1-14 copies per protein,either as the sole globular domain or in combination wih β-helix-forminghexapeptide repeats as is the case of sequestrin. It is generally found intandem pairs of A-type and B-type domains. Previously believed to be exclusiveto Plasmodium, the 6-Cys domain also exists in proteins found in all membersof the aconoidasidan (hematozoan) clade of Apicomplexa, which unites thehaemosporidians (Plasmodium) and piroplasms) [, , , , ].The 6-cys domain is a β-sandwich formed by two sheets with a mixture ofparallel and antiparallel strands. Three disulfide bonds arepresent in the 6_Cys domain with C1-C2, C3-C6, and C4-C5 connectivity. C1-C2and C3-C6 pin together the two sheets of the β-sandwich, whereas C4-C5links an ancyllary loop to the core domain [, ].Some Plasmodium proteins known to contain a 6-Cys domain are listed below:Pfs48/45, involved in male/female gamete fusion in the mosquito midgut. Itis predicted to be glycosylphosphatidylinositol (GPI)-anchored to thegamete surface.Pfs230, involved in male/female gamete fusion in the mosquito midgut. It isa soluble protein that associates with the gamete membrane by binding toPfs48/45.Pfs47, involved in male/female gamete fusion in the mosquito midgut. It isfound on female gametes.P52, expressed in the sporozoite. May be required for invasion ofhepatocytes and to promote normal development in the liver.P36, expressed in the sporozoite. May be required for invasion ofhepatocytes and to promote normal development in the liver.Pf41, located on the surface of merozoites and has a signal sequence.Pf38, located on the surface of merozoites. It has a signal sequence and isGPI-anchored to the merozoite surface.Pf12, located on the surface of merozoites. It has a signal sequence and isGPI-anchored to the merozoite surface.Pf92, located on the surface of merozoites. It has a signal sequence and isGPI-anchored to the merozoite surface. |
