The reduced (aka "Niggli") cell for your case is 82.8246 88.2997 82.8246
98.8892 110.5181 117.0456
You can get this using "tracer" or "othercell" in the CCP4 suite.
I keep a local table of reduced cells from the PDB that I update
periodically, and the closest one to yours in that list is:
4y42 82.5 88.0 82.5 99 110 117 cyanate hydratase
This was deposited in P1, but if you download the data and feed it to
Pointless, it is quite confident that the true space group is actually
C2. There are 10 chains in the ASU so there may be some pseudo symmetry
going on. The paper reporting 4y42 describes it as a " serendipitous
crystallization".
What happens if you try to refine your data against the model deposited
as 4y42?
Hope that helps,
-James Holton
MAD Scientist
On 6/17/2017 12:07 AM, dongxiaofei wrote:
Dear ALL,
I got two kinds of crystals of different proteins ,but there are many
similarities.
The shape of the crystals are similar, the cell parameters are also
similar :
protein A , 136.12 94.398 89.476 90 125.479 90 , Space group C
1 2 1 and
protein B , 136.14 94.369 89.115 90 125.495 90 , Space group
C 1 2 1.
protein A has a NMR structure ,but Rfree always high above 50% after
molecular replacement , protein B’s Rfree is also above 50% .
So I am wonder if these crystals are the result of debris of proteins
, because the growth of the crystals needs more than half a year . I
am sure the two proteins are different and crystals respectively come
from different proteins
Any insights will be really appreciated.
Thanks
Dong Xiao
