Table 3. Selected bond angles and torsion angles of the phosphate group of the phosphotyrosine (degrees).
| CD28 a | Small molecule crystallography b | REFMAC c | ||
| A | B | |||
| Bond angles | ||||
| Cζ–Oη–P | 129.6 | 125.5 | 122.8 | 120.0 |
| Oη–P–O1P | 94.7 | 103.2 | 108.3 | 108.2 |
| Oη–P–O2P | 106.4 | 104.5 | 106.8 | 108.2 |
| Oη–P–O3P | 110.8 | 106.9 | 103.7 | 108.2 |
| (Average of Oη–P–OnP) | (104.0) | (104.9) | (106.3) | (108.2) |
| O1P–P–O2P | 112.9 | 106.5 | 111.0 | 119.9 |
| O2P–P–O3P | 115.6 | 121.5 | 111.4 | 119.9 |
| O3P–P–O1P | 114.1 | 112.5 | 115.0 | 119.9 |
| Torsion angles | ||||
| Cζ–Oη–P–O1P | –149.0 | –85.4 | 61.2 | – |
| Cζ–Oη–P–O2P | –33.4 | 25.7 | 178.8 | – |
| Cζ–Oη–P–O3P | 93.0 | 155.6 | –58.5 | – |
| (Rotation O1P →O2P) | (115.6) | (111.1) | (117.6) | (120.0) |
| (Rotation O2P →O3P) | (126.4) | (129.9) | (122.7) | (120.0) |
| (Rotation O3P →O1P) | (118.0) | (119.0) | (119.7) | (120.0) |
a
Present work.
b
Results from small-molecule X-ray crystallography [21]. As the asymmetric unit contains 2 phosphotyrosine molecules, denoted A and B, the values for both are shown.
c
Values from the dictionary files of REFMAC.