Lysozyme

Two scans were collected on a 250 micron lysozyme crystal in 1.5 minutes 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 37 mm -88° 56.25° 0.25° 195° 28.6° 225 0.2 sec 45 sec
2 37 mm -90° 56.25° 0.25° 225 0.2 sec 45 sec

The data set was processed with HKL-3000R; it was complete to 1.75 Å with a low multiplicity and Rmerge. Using a resolution of 2.1 Å, SHELXD located 9 sulfurs and these were subsequently used in phasing to 2.0 Å with SHELXE and MLPHARE and density modification to 1.75 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 lysozyme structure with an R = 16.5 % and Rfree = 21.4 %.

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

lysomap

Scaling statistics

Space group P4₃2₁2
Unit cell lengths (Å)
      angles (˚)
77.6, 77.6, 37.9
90, 90, 90
Resolution (Å)
(last shell)
30-1.75
(1.78-1.75)
Completeness (%)
(last shell)
96.9
(81.9)
Multiplicity
(last shell)
6.8
(2.5)
<I>/<σI>
(last shell)
52.8
(8.1)
R-merge (%)
(last shell)
3.3
(13.5)