I think you have a found a supercell and dont really need to run any MR
program to find the solution - just reposition the molecule
Your P422 point group cell is
126.514 126.514 76.766 90.00 90.00 90.00
Your I422 point group cellis:
180.096 180.096 152.530 90.00 90.00 90.00
Note c
Actually, another thing could be going on as well. You show a large
off-origin peak in the Patterson in I422 so you may have
pseudotranslation going on and you processed in the supercell. You could
probably try to reindex choosing fewer spots and get your P422 cell. I
am sure there is some law
To complicate things some more, a couple of things could be going on.
1. You could have pseudosymmetry, where you true SG is I4 and the
additional NCS operators make the crystal look I422.
2. You could have twinning. If merohedral, could be I4. If
pseudomerohedral, could be any of the subgrou
also try MOLREP (CCP4i) - we had a case where AMORE and PHASER did not
work (in our hands), but MOLREP did, using the internal MOLREP
sequence alignment/unequal amino acid trimming feature.
This was a case of a P1 cell with 12 copies of the same molecule, 2.3A
resolution, not very high-qualit
I would also try Open-EPMR as well as Phaser. It
can sometimes find solutions that Phaser or Amore cannot, especially
for multiple chains and low resolution. EPMR is especially good at
handling high copy numbers of search models.
Cheers.
Pete Meyer wrote:
A few
things to try (or double-check
A few things to try (or double-check):
1. If you ran phaser with SGALTERNATIVE ALL, make sure the mtz file you
gave to refmac has the same screw axes as the MR solution. If this is
off, it'll lead to higher R-factors.
2. As Fred mentioned, try with a single copy of the protein, and check
th
Hi there,
2 things:
Are you sure that the relative orientations of your components are the same in
the different crystal forms? If you haven't done it already, it would be worth
while trying to search for the individual components as well (could be
difficult because your components are not so
Dear CCP4 community:
Sorry if there is a duplicate post. I am a beginner to crystallography and
therefore my
apologies if this question is too simple.
Basically we obtained several crystal forms of the same molecule, which is a
hetero-
trimer containing protein A(18kD), protein B(16kD) and a R
Dear CCP4 community:
I am a beginner to crystallography and therefore my apologies if this question
is too
simple.
Basically we obtained several crystal forms of the same molecule, which is a
hetero-
trimer containing protein A(18kD), protein B(16kD) and a RNA segment(40nt or
about
15kD).
W
