TABLE 1.

Possible conformations of His-37 and Trp-41

Dihedral angles (°)
His-37		Trp-41		Rotamers
χ1	χ2	χ1	χ2	His-37	Trp-41
160–170	190–200	150–160	280–290	t-160	t-105
160–170	160–190	170–210	090–100	t-160	t90
150–160	50–70	150–170	270–290	t60	t-105
150–160	050–110	160–210	090–100	t60	t90

The dihedral angles were obtained via conformation scan with a discretization of each angle by 10°. These conformations do not have steric clashes and are consistent with both the NMR restraint (d_δ-γ ≤ 3.9 Å) (31) and the penultimate rotamer library (32). The PRL rotamer nomenclature is used here.