PMC9929429_01
Partial sequencing map of the patient's XK gene. The orange dotted box shows the c.942G>A variation. The asterisk shows the tryptophan change to a stop codon located at the 314 position of the XK protein.
fgene-14-1073139-g002.jpg
PMC9929429_01_fgene-14-1073139-g002.jpg
F2
Transfusion (ISBT) blood group database (Figure 2). This variation leads to a premature stop codon at position 314 and results in an incomplete C-terminally truncated protein (p.Trp314Ter) (Figure 2). The nucleotide sequence of the allele has been submitted to the GenBank database with the accession number OK18693.
Structural analysis of the patient's truncated XK protein. (A) Schematic diagram of the 10-transmembrane structure of the XK protein. The blue column indicates the retained transmembrane structure of the truncated XK protein; the dotted line and gray column represent deleted structures of the truncated protein, including the last two transmembrane structures, the last extracellular domain, and the entire C-terminal intracellular peptide segment. The red dots are binding sites XKCys347-KellCys72. This schematic representation is based on the base model constructed by. (B) Comparison of 3D conformations of mutant and wild-type XK proteins. The red and blue areas represent the overlapping regions; the blue dashed box is the deleted structure; the globular amino acid structure represents the truncation point of the protein. The rod-shaped amino acid indicated by the black arrow corresponds to the missing binding site of the Kell blood group system.
fgene-14-1073139-g003.jpg
PMC9929429_01_fgene-14-1073139-g003.jpg
F3
The result showed that the incomplete XK protein lacked the binding site for the Kell antigen (Figure 3).