Re: [ccp4bb]: crystal packing effects

[Ed Lattman]

Were some of these crystals frozen and some not?  Brian Matthews has documented significant changes in side chain conformations between structures done at room temperature and flash frozen from the same crystal form. Ed Eaton E. Lattman Dean of Research and Graduate Education Professor of Biophysics Krieger School of Arts and Sciences JHU 410 516-8215 voice 410 516-4100 fax On Jan 17, 2006, at 9:40 AM, Richard Gillilan wrote: ***  For details on how to be removed from this list visit the  *** ***          CCP4 home page http://www.ccp4.ac.uk         *** I was surprised when I compared the high-resolution structures of lysozyme grown in three different space groups. The overall backbone RMSD were 0.7A. This seems large to me, I remember reading somewhere that 0.25A was more typical of identical proteins grown by different groups under different conditions. Is anyone aware of a systematic comparison of identical proteins in different space groups? When looking for small changes in protein structure induced by ligand binding, one should ideally compare like space groups, but that is often not possible. The case is strengthened when similar changes are seen in different space groups. Does anyone have advice to offer on how to separate packing effects from true ligand-induced changes in ambiguous cases? Richard Gillilan MacCHESS