Skip to main content

Table 1 HLA–DRB1 amino acid sequence for alleles observed among rheumatoid arthritis patients and their classification according to du Montcel and colleagues

From: A new classification of HLA-DRB1 alleles differentiates predisposing and protective alleles for autoantibody production in rheumatoid arthritis

HLA-DRB1 allele Amino acid position Classification of du Montcel and colleagues
  69 70 71 72 73 74 75 76  
HLA-DRB1*0101 E Q R R A A V D S3P
HLA-DRB1*0102 - Q R R A A - - S3P
HLA-DRB1*0103 - D E R A A - - S1
HLA-DRB1*03 - - K - G R - - X
HLA-DRB1*0401 - Q K R A A - - S2
HLA-DRB1*0402 - D E R A A - - S1
HLA-DRB1*0403 - - - - - E - - X
HLA-DRB1*0404 - Q R R A A - - S3P
HLA-DRB1*0405 - Q R R A A - - S3P
HLA-DRB1*0407 - - - - - E - - X
HLA-DRB1*0408 - Q R R A A - - S3P
HLA-DRB1*0411 - - - - - E - - X
HLA-DRB1*07 - D - - G Q - - X
HLA-DRB1*08 - D - - - L - - X
HLA-DRB1*0901 - R - - - E - - X
HLA-DRB1*1001 - Q R R A A - - S3P
HLA-DRB1*1101 - D R R A A - - S3D
HLA-DRB1*1102 - D E R A A - - S1
HLA-DRB1*1103 - D E R A A - - S1
HLA-DRB1*1104 - D R R A A - - S3D
HLA-DRB1*12 - D R R A A - - S3D
HLA-DRB1*1301 - D E R A A - - S1
HLA-DRB1*1302 - D E R A A - - S1
HLA-DRB1*1303 - D K R A A - - S2
HLA-DRB1*1323 - D E R A A - - S1
HLA-DRB1*1401 - R - - - E - - X
HLA-DRB1*1402 - Q R R A A - - S3P
HLA-DRB1*1404 - R - - - E - - X
HLA-DRB1*15 - Q A R A A - - S1
HLA-DRB1*16 - D R R A A - - S3D
  1. In the du Montcel and colleagues classification [35], the HLA–DRB1 alleles were first divided into two groups according to the presence or absence of the RAA sequence at positions 72–74, which denote S and X alleles (respectively shared epitope and nonshared epitope alleles). The S alleles were subsequently divided into four groups according to the two first amino acids at positions 70 and 71 (boldface): S1 for ARAA and ERAA, S2 for KRAA, S3 for RRAA (divided into S3P for QRRAA and S3D for DRRAA according to position 70), and X for all non-RAA motifs. The conventional classification of the amino acids was used, here divided into three biochemical subgroups, as follows: group 1 = G for glycine, A for alanine, V for valine, L for leucine (aliphatic amino acids (nonpolar hydrophobic)); group 2 = K for lysine, R for arginine (basic amino acids (polar and positively charged)); group 3 = E for glutamic acid, Q for glutamine (the amide corresponding to E), D for aspartic acid, and N for asparagine (the amide corresponding to D) (acidic amino acids and corresponding amides are very hydrophilic; acidic amino acids are polar and negatively charged at physiologic pH, amides are polar and uncharged, and not ionizable) [36].