SOS - Save Our Structure factors !!

Gerard DVD Kleywegt gerard at
Fri May 16 15:26:37 EST 2003

(This is a request for help from all the world's macromolecular
crystallographers who have deposited structures in the PDB.)


Dear colleague !

At present, structure factor data are available for only about *half* of all
crystal structures in the PDB. Unless we all make a serious effort now, we
must fear that these data will be lost to science for all eternity.  
Therefore, we would like to encourage all macromolecular crystallographers to
check if any of their PDB entries perhaps do not have the associated structure
factors deposited. To help you do this, a simple form to query the RCSB
database is available at this URL:


Simply type (a unique part of) your name and hit the "Check" button to get a
list of any and all such entries. If there are any, please try and track down
the structure factors (on old disks, tapes, or by asking former students and
post-docs, etc.) before they are lost forever. If you find any, please send
them to the RCSB (mailto:deposit at (By the way: the most
likely future user of deposited structure factor data are you yourself !!)

As you may know, we have been working on creating an archive of electron
density maps for all crystal structures in the PDB for which structure factor
data have been deposited - the Uppsala Electron Density Server (EDS; URL: At present, in about one percent of cases, we are
unable to calculate a map at all, and for another ~15% of cases we are unable
to reproduce the published R-value to within five percentage-points. The
webpage with the search form mentioned above also contains a request for you
to help us improve our ~85% success rate with EDS map calculations.

These two initiatives combined will help to preserve and improve the wealth of
macromolecular crystallographic data in the public databanks and to make them
available and easily accessible to the entire scientific community (cell and
molecular biologists, medicinal chemists, crystallographers, etc. etc.) now
and in the future.

Thank you for your time and help in advance !!

--Gerard Kleywegt & Alwyn Jones

P.S.: please direct technical correspondence about EDS to eds at

P.P.S.: in this request it has been tacitly assumed that coordinates of all
published structures have been deposited already. In cases where this is not
so, you are of course also strongly encouraged to dig up the models and
deposit them together with the corresponding structure factors.

P.P.P.S.: please help this initiative by bringing it to the attention of
colleagues who may not read the electronic crystallographic bulletin boards.

                        Gerard J.  Kleywegt
    [Research Fellow of the Royal  Swedish Academy of Sciences]
Dept. of Cell & Molecular Biology  University of Uppsala
                Biomedical Centre  Box 596
                SE-751 24 Uppsala  SWEDEN  mailto:gerard at
   The opinions in this message are fictional.  Any similarity
   to actual opinions, living or dead, is purely coincidental.


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