A data set has been collected on a crystal of protein Y at cryo temperature. The data were collected by Eric Huizinga, end of May 1996, at the University of Utrecht (The Netherlands, Department of Crystal- and Structural Chemistry) with a DIP2000 detector. The spindle axis comes from the left seen from the direction of the beam, and lies with the beam in the horizontal plane.
The unit cell of the crystal is 35.3 98.7 44.6 90 90.7 90, space group . A copper rotating anode was used (), the crystal to detector distance was 100 mm. No theta offset was used: x beam 99.75 y beam 100.10.
After indexing, refinement and integration of the first frame, STRATEGY was run with the COMPleteness 98 95 92 90 88 85 82 80 option. The global minimal oscillation ranges for the different total completenesses are given in the following table.
Table: Minimal oscillation ranges for different completenesses for datacollection on protein Y
Figure shows the minimal needed oscillation range as a function of the starting spindle angle for a 85% complete data set in the resolution range of 20 - 2.05. There is a minimum around zero degrees. Starting around zero, the total sweep needed for a data set of at maximum 85% completeness is a bit less than 60 degrees. This crystal was used as a fast check of the quality of a new batch of crystals. Normally, one would collect 180(!) degrees to get a good, complete data set with enough redundancy for a monoclinic crystal.
Figure: Minimal total oscillation range as function of the starting spindle angle for
a 85% complete data set of Protein Y (Monoclinic)
In total 57 frames of 1.0 degree oscillation were collected, starting at an
oscillation angle of 0 degrees.
Complete dataprocessing of these frames (indexing, refinement, integration, scaling
and rejection of the bad merging reflections) using
DENZO and SCALEPACK gave the following redundancy table:
Shell Summary of observation redundancies by shells:
Lower Upper No. of reflections with given No. of observations
limit limit 0 1 2 3 4 5-6 7-8 9-12 13-19 >19 total
20.00 5.03 414 362 425 77 21 0 0 0 0 0 885
5.03 4.00 325 479 379 82 20 0 0 0 0 0 960
4.00 3.50 272 567 349 78 13 0 0 0 0 0 1007
3.50 3.18 245 600 324 86 4 0 0 0 0 0 1014
3.18 2.95 232 652 324 78 1 0 0 0 0 0 1055
2.95 2.78 219 661 314 81 1 0 0 0 0 0 1057
2.78 2.64 200 688 311 65 1 0 0 0 0 0 1065
2.64 2.53 205 708 288 61 0 0 0 0 0 0 1057
2.53 2.43 186 743 292 64 0 0 0 0 0 0 1099
2.43 2.35 177 731 286 52 0 0 0 0 0 0 1069
2.35 2.27 171 772 293 53 0 0 0 0 0 0 1118
2.27 2.21 181 752 275 48 0 0 0 0 0 0 1075
2.21 2.15 166 775 295 37 0 0 0 0 0 0 1107
2.15 2.10 167 758 291 42 0 0 0 0 0 0 1091
2.10 2.05 188 763 277 33 0 0 0 0 0 0 1073
All hkl 3348 10011 4723 937 61 0 0 0 0 0 15732
Table of redundancy and completeness for a data collection of 57 frames,
starting at the spindle angle 0.00 and with an oscillation range of 1.00 degree(s).
Shell Summary of predicted redundancies by shells:
Lower Upper No. of reflections with given No. of predictions
limit limit 0 1 2 3 4 5-6 7-8 9-12 13-19 >19 completeness
20.00 5.03 394 374 432 76 23 0 0 0 0 0 69.67
5.03 4.00 315 483 384 83 20 0 0 0 0 0 75.49
4.00 3.50 268 570 350 76 15 0 0 0 0 0 79.05
3.50 3.18 238 605 327 86 4 0 0 0 0 0 81.11
3.18 2.95 226 653 326 80 1 0 0 0 0 0 82.43
2.95 2.78 211 666 317 80 3 0 0 0 0 0 83.48
2.78 2.64 193 691 314 68 1 0 0 0 0 0 84.77
2.64 2.53 198 705 291 62 0 0 0 0 0 0 84.24
2.53 2.43 184 742 302 65 0 0 0 0 0 0 85.77
2.43 2.35 163 732 288 52 0 0 0 0 0 0 86.80
2.35 2.27 172 776 301 53 0 0 0 0 0 0 86.79
2.27 2.21 173 736 281 48 0 0 0 0 0 0 86.03
2.21 2.15 161 765 308 40 0 0 0 0 0 0 87.36
2.15 2.10 164 760 305 42 0 0 0 0 0 0 87.10
2.10 2.05 180 758 285 35 0 0 0 0 0 0 85.69
All hkl 3240 10016 4811 946 67 0 0 0 0 0 83.02
This table corresponds very well with the prediction
of STRATEGY, based on the first integrated
frame with the NFRAme 57 command.
STRATEGY predicts just a bit more reflections than have actually been measured.
The good agreement between the prediction and the actual measurements are due to the special
properties of this crystal: low mosaicity (0.22) and high scattering power (average I/sig
highest resolution shell is larger than 10).