Dear colleagues,
here is one cunning plan:
to quickly evaluate the anomalous signal of a test data set with a
non-interactive script that:
1. solves the structure using SAD
2. does some solvent flattening
3. compares the resulting phases against calculated phases from a
refined, isomorphous structure. Generates some "global" measure of
phase error (deviation from refined, calculated phases).
Not very original, but still failing in my hands.
1., 2. (shelxc/d/e) - check.
3. a) take model amplitudes, phases and weights (F, PHIC, FOM(C)) from
a refmac MTZ file - check.
3. b) cad PHI, FOM from the shelxe output with the selected columns
from the refmac MTZ - check.
3. c) display reasonable maps using either of F-PHIC-FOM(C) or
F-PHI-FOM combinations - check.
3. d)
cphasematch -mtzin cad_ori.mtz -mtzout phasematch.mtz \
-colin-fo "/*/*/[F,SIGF]" -colin-phifom-1 "/*/*/[PHIC,FOM]" \
-colin-phifom-2 "/*/*/[PHI_ori,FOM_ori]"
Now, I did expect to see a reasonable map using the F-
phasematch.Phi_fom.phi-phasematch.Phi_fom.fom combination that would
resemble F-PHI-FOM, but superimposed onto F-PHIC-FOM(C). But the F-
phasematch.Phi_fom.phi-phasematch.Phi_fom.fom map does not resemble
the protein structure at all.
It is slowly coming to me that I must be doing this the wrong way. Can
anyone spot the problem? By the way, the crystal is cubic insulin
(a=78 A.) I would be happy to send out the data, the phasematch.mtz is
just 140 kB in size.
Many thanks,
Wolfram Tempel
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