Table 6. Type 1 diabetes associated polymorphic residues of DQB1 alleles with a proposed function.
| DQB1 allele | Amino Acid position | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| HH | TCR | ||||||||||||||||||
| HB | SB | ||||||||||||||||||
| P4 | P4 | P4/7 | P6 | P9 | P7 | P9 | P7 | P4 | P4/7 | P4 | P1 | P1 | P1 | P1 | |||||
| 13 | 26 | 28 | 30 | 37 | 47 | 52 | 53 | 55 | 57 | 66 | 67 | 70 | 71 | 74 | 85 | 86 | 89 | 90 | |
| Susceptibility alleles | |||||||||||||||||||
| 02:01 | G | L | S | S | I | F | L | L | L | A | D | I | R | K | A | L | E | T | T |
| 03:02 | G | L | T | Y | Y | Y | P | L | P | A | E | V | R | T | E | L | E | T | T |
| Protective alleles | |||||||||||||||||||
| 03:01 | A | Y | T | Y | Y | Y | P | L | L | D | E | V | R | T | E | L | E | T | T |
| 05:03 | G | G | T | H | Y | Y | P | Q | P | D | E | V | G | A | S | V | A | G | I |
Positions identified in bold show amino acids that are exclusive to the type 1 diabetes positively or negatively associated 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, SB; salt bridge, TCR; site of contact of HLA molecule to T-cell receptor.