Hakon Hope (hhope at ucdavis.edu) wrote:
: In the March 7, 1996 issue of Nature (p 27) appears an
: article that among other items contains the following
: description of present-day methods for structure
: determination from x-ray data:
: "Such structure determinations must still be done by a
: trial-and-error methodology, in which diffraction spot
: intensities are calculated for various possible atomic
: geometries and compared with experimental intensities."
: (This is just part of the description. The article
: contains more, equally valuable information.)
: I may be overly sensitive, but it seems to me that both the
: journal and the authors need an explanation of how
: crystallographers go about their business.
: Any suggestions?
Dear Hakon,
A letter to the editor from a long-time xtalogrfr, such as you,
might go a long way. I suppose the quote applies, to a limited degree,
to the process of refinement, where trial structures for proteins are
constructed from aa residues and placed in physically/chemically reason-
able positions, and the residual is minimized. They are obviously over-
looking both the phasing to get the initial density map and such proceed-
ures as energy minimization to select likely conformations.
Yours,
Bill Tivol
