Model of topology for RhAG, RhCE, and RhD.
RhAG (Mr 50 000) consists of 409 amino acids and is encoded by RHAG on chromosome 6p11-p21.1. RhCE and RhD (Mr 30 000) are predicted to have a similar topology and are encoded by RHCE and RHD, which are adjacent on chromosome 1p34-p36. The domain of the RhD protein encoded by each exon is depicted by numbered boxes, which represent the start and finish of each exon. Of the D-specific amino acids, 8 are on the exofacial surface (yellow ovals), and 24 are predicted to reside in the transmembrane and cytoplasmic domains (black ovals). Red ovals represent amino acids that are critical for C/c (Ser103Pro) and E/e (Pro226Ala) antigens; purple ovals represent Ser103 and Ala226 on RhD. The zigzag lines represent the Cys-Leu-Pro motifs that are probably involved in the palmitoylation sites. The N-glycan on the first loop of RhAG is indicated by the branched structure of red circles.
