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Hello,
I wanted to make an anomalous difference fourier map of a
structure with zinc bound to it. However I have not been successful in making
the map and I would really appreciate your help if anyone could suggest me
where I am going wrong.
I solved this zinc bound structure, by molecular replacement from a calcium
bound structure (1.4 angstrom) that I solved. I want to show that the zinc
binds to the identical site by the anomalous difference fourier map.
I am using CCP4i and the steps that I have been taking are, (names of the files
are arbitrary)
1) generating structure factors and phases from the solved coordinates by SFALL
Input files
zinc bound pdb
original zinc .mtz data from synchrotron
output file
XXXXsfall.mtz
2)merging the XXXXsfall.mtz containing the PHICalc and FCalc columns with the
original synchrotron .mtz file containing DANO and SIGDANO by running CAD.
input files
XXXXsfall.mtz and zinc synchrtron .mtz
output file
CAD.mtz
3) Running FFT to make anomalous map, selecting labels from CAD.mtz as input
files.
There is an output map file but nothing in it. all the values are 0 and the map
is not recognized by coot. There is no error message in the log file.
I must be missing something or doing something wrong/stupid.
Thanks,
Ivan