Thaumatin

Three scans were collected on a 250 micron thaumatin crystal in 4 minutes and 16 seconds using the FR-X, a VariMax HF optic, and the PILATUS 200K.

Data collection parameters

Scan # Distance ωstart ω range Δω φ χ # img Exposure per image Total Exposure
1 70 mm -35° 70° 0.25° -108° 13° 280 0.2 sec 56 sec
2 70 mm -35° 70° 0.25° 72° 13° 280 0.2 sec 56 sec
3 70 mm -67° 170° 0.25° 72° 26° 23° 720 0.2 sec 2 min 24 sec

The data set was processed with HKL-3000R; it was complete to 1.69 Å with a low multiplicity and Rmerge. Using a resolution of 2.7 Å, SHELXD located 9 sulfurs (8 disulfides and 1 methionine) and these were subsequently used in phasing to 1.8 Å with SHELXE and MLPHARE and density modification to 1.69 Å with DM. A model was built into the experimental electron density map using ARP/wARP, and quick model adjustments and refinement with REFMAC produced a thaumatin structure with an R = 15.1 % and Rfree = 17.7 %.

2Fo-Fc map (gray, 2.2 σ) and
anomalous difference map (magenta, 5 σ)

Scaling statistics

Space group P4₁2₁2
Unit cell lengths (Å)
      angles (˚)
57.9,57.9,149.8
90, 90, 90
Resolution (Å)
(last shell)
30-1.69
(1.72-1.69)
Completeness (%)
(last shell)
99.6
(96.5)
Multiplicity
(last shell)
6.8
(3.0)
<I>/<σI>
(last shell)
38.1
(6.9)
R-merge (%)
(last shell)
4.0
(15.0)