You dont give the resolution of your data.
There are always things to check
1) space group - could it be P222 or P21 2 2 or P 21 21 2 or P2 21 2
etc etc - there are 8 possibilities.
You can use absences along the axial lines to help decide on the screw
axes, but these can be misleading if you have more than 1 molecule in
the asymmetric unit and the molecules are related by a
non-crrystallographic translation. Phaser can be run in each space group
in turn and usually that can decide on SG. Did you do that?
2) Is there a problem with the data - severe anisotropy? twinning? etc etc
3) Maybe you just need to do more rebuilding - depending on
theresolution some of the automated procedures can help - Arp/wARP,
buccaneer and so on..
Eleanor
ManojSaxena wrote:
Hi all,
I am working with a protein that have 28% similar to my MR template.
I have processed data in HKL2000 for one of my crystal and I got unique sol in
space group
P212121. with LLG 131 and TFZ score 13.5
I have used buccaneer and coot for model building and my Rfee came to 45%.
I used the PDB file from this crystal ( Rfee of 45%) as my MR model for data obtained from
another crystal and got sol with TFZ score=40.5 and LLG=2305.
I used coot and did a round of refmac refinement now my Rfee is 41%.
My concern is
a) wether my scheme is good or not because I am afraid that this will increase the model
bias.
b)Now I am stuck at 41% Rfee I have many chain breaks and loop regions have not good
density. I tried TLS refinement it did not help. what else I shall try??
Thanks
Manoj
PSU
Biochemistry
