Dear all
I have a molecular replacement problem and I really need your help
with this one. My protein crystallized in C2 instead of P21 like it
did before. Now when I tried to do MR to place it in C2 it doesn't
work, I get no solution. This protein has been crystallized in
P212121, P31, P43 and C2 and it has two loops in different regions
that depending on the packing, they'll show density so it is flexible.
When I crystallized it the first time in P21 and used a publish model
I had no problem at all to place it, just right now. I've have tried
molrep, phaser and phenix with different resolution ranges (40-3.0,
20-3.0, 10-3.0) and different models, i.e. publish structures or the
one I got at P21. I also tried doing rotation first at different
resolutions then compare the peaks obtained and picked the ones that
are consistent and give that for translation search and yet no
solution. The resolution is 2.4 A and the Matthews coefficient
predicts 3 molecules in ASU with 43.6% solvent. I also tried searching
for 2 molecules just in case that it is high solvent content (62.5%)
as monomer and as dimer and yet no solution. The data itself processed
well and I've processed in HKL and d*trek and used both processed
files and yet no solution. Completeness is 96.9% overall and 82%
(2.49-2.40) shell. Redundancy is 3.5 overall and 2.6 at the(2.49-2.40)
shell. Here is the table from HKL:
Lower Upper Average Average Norm. Linear Square
Angstrom I error stat. Chi**2 R-fac R-fac
50.00 5.17 901.9 35.9 10.2 1.105 0.041 0.051
5.17 4.10 962.8 47.7 11.6 0.971 0.045 0.049
4.10 3.58 496.4 25.9 9.2 1.194 0.063 0.067
3.58 3.26 309.9 15.2 8.4 1.360 0.069 0.067
3.26 3.02 153.9 9.9 7.2 1.456 0.105 0.098
3.02 2.85 100.8 7.3 6.9 1.864 0.141 0.120
2.85 2.70 57.4 7.0 6.8 1.584 0.200 0.162
2.70 2.59 41.9 7.5 7.0 1.348 0.246 0.220
2.59 2.49 30.5 7.4 7.3 1.526 0.329 0.285
2.49 2.40 22.5 8.0 7.8 1.347 0.388 0.361
All reflections 319.9 17.6 8.3 1.366 0.065 0.056
Would you please, please give me some tips, tricks, advice,
encouragement? :-)
Thank you so much
Teresa
Teresa De la Mora-Rey Ph.D.
Dept. Medicinal Chemistry
University of Minnesota
8-101 Weaver-Densford Hall
308 Harvard St. SE, Minneapolis, MN 55455
Lab phone (612) 626-5226
"If you never did you should. These things are fun and fun is good"
Dr. Seuss
