Background:
HLA-G belongs to the HLA class I heavy chain paralogues. This class I molecule is a heterodimer consisting of a heavy chain and a light chain (beta-2 microglobulin). The heavy chain is anchored in the membrane. HLA-G is expressed on fetal derived placental cells. The heavy chain is approximately 45 kDa and its gene contains 8 exons. Exon one encodes the leader peptide,exons 2 and 3 encode the alpha1 and alpha2 domain,which both bind the peptide,exon 4 encodes the alpha3 domain,exon 5 encodes the transmembrane region,and exon 6 encodes the cytoplasmic tail.