Table 5. Type 1 diabetes associated polymorphic residues of DRB1 alleles with a proposed function.
| DRB1 allele | Amino Acid position | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| HB | HH | ||||||||||||
| TCR | TCR | CD4 | |||||||||||
| P9 | P6 | P4 | P4 | P9 | P9 | P7 | P7 | P4/7 | P4 | ||||
| 9 | 11 | 13 | 26 | 37 | 57 | 67 | 70 | 71 | 74 | 77 | 112 | 140 | |
| Susceptibility alleles | |||||||||||||
| 03:01 | E | S | S | Y | N | D | L | Q | K | R | N | H | T |
| 04:01 | E | V | H | F | Y | D | L | Q | K | A | T | H | T |
| 04:05 | E | V | H | F | Y | S | L | Q | R | A | T | H | T |
| Protective alleles | |||||||||||||
| 10:01 | E | V | F | V | Y | D | L | R | R | A | T | H | T |
| 11:04 | E | S | S | F | Y | D | F | D | R | A | T | H | T |
| 14:01 | E | S | S | F | F | A | L | R | R | E | T | Y | T |
| 16:02 | W | P | R | F | S | D | L | D | R | A | T | H | A |
Positions identified in bold show amino acids that are exclusive to the type 1 diabetes susceptibility or protective alleles. The function associated with each amino acid is depicted on top. P; pocket (peptide binding), HH; homodimer of heterodimer, HB; hydrogen bond to peptide, TCR; site of contact of HLA molecule to T-cell receptor. CD4; site of contact of HLA molecule to CD4.