Description and molecular modeling of a novel human leukocyte antigen allele: A*32:22

We describe here the sequence and the molecular modeling of a new variant of HLA-A*32 allele officially named A*32:22. This novel allele has been detected in an Italian cord blood sample by sequence-based typing (SBT). The mutation (CAT →CGT), which has occurred at codon 151, at nucleotide position 524, implies an amino acidic change from Histidine to Arginine. Residue 151 is located on top of the molecule inside the region contacted by T cell receptor (TCR) and it is possibly involved in docking TCR. A positively charged residue is maintained on this position determining a slight change of electrostatic potential on the molecular surface. This suggests a limited functional relevance of the amino acid substitution encoded by A*32:22.