In answer to:
>>We have a protein that coordinates Ca2+. The electron density is oblong
>instead of spherical. This is true in both the Fo-Fc without Ca2+ in the model
>and in the 2Fo-Fc with Ca2+.
>>Does any one else see this non-spherical density phenomenom in a Ca2+ (or other
>metal ion) coordinating a macromolecule?
>
Your data may represent an average of two states of the protein, with the
metal in a slightly different position in each. This was the case for one
xylose isomerase structure.
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Miriam Hasson
Assistant Professor
Purdue University
Department of Biological Sciences
Lilly Hall of Life Sciences
West Lafayette, IN 47907-1392
Telephone: (317)496-2928, 496-1984
Fax: (317)496-1189
E-mail: mhasson at bragg.bio.purdue.edu
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