This family includes the folate receptor which binds to folate and reduced folic acid derivatives and mediates delivery of 5-methyltetrahydrofolate to the interior of cells. These proteins are attached to the membrane by a GPI-anchor. The proteins contain 16 conserved cysteines that form eight disulphide bridges.

1: Positions of disulfide bonds in riboflavin-binding protein of hen egg white. Hamazume Y, Mega T, Ikenaka T; J Biochem (Tokyo) 1987;101:217-223. PMID:3571203