Cluster Of Differentiation 200 (CD200)

CD200 protein encoded by this gene is a type-1 membrane glycoprotein, which contains two immunoglobulin domains, and thus belongs to the immunoglobulin superfamily. The MRC OX-2 antigens purified from thymocytes and brain are glycoproteins of a molecular mass of 47,000 and 41,000 daltons containing 33% and 24% carbohydrate, respectively.

Protein and cDNA sequencing showed that these antigens contain 248 amino acids, of which 202 are likely to be outside the cell, with a single transmembrane sequence and 19 residues on the cytoplasmic side. The extracellular part contains 2 domains with sequence similarities to immunoglobulin domains, establishing MRC OX-2 as a member of the immunoglobulin superfamily.