Is it possible the solution structure of SAXS, NMR and EM neglect the existence of a very small percentage conformation of the molecule due to the overwhelming signals from the majority conformations? But this state of the molecule is trapped and enriched by the crystallization condition.
Nian On Sat, Feb 11, 2012 at 1:10 PM, Poul Nissen <p...@mb.au.dk> wrote: > Another good lesson here: > > 2. > The SAXS solution structure of RF1 differs from its crystal structure and > is similar to its ribosome bound cryo-EM > structure.<http://www.ncbi.nlm.nih.gov/pubmed/16364917> > *Vestergaard B*, Sanyal S, Roessle M, Mora L, Buckingham RH, Kastrup JS, > Gajhede M, Svergun DI, Ehrenberg M. > Mol Cell. 2005 Dec 22;20(6):929-38. > > On 11/02/2012, at 18.18, Joel Sussman wrote: > > 2012_02_11 > Dear All, > Two really striking examples of "Intrinsically Flexible Proteins" are: > > (1) *Adenylate kinase*: Vonrhein, Schlauderer & Schulz (1995) *Structure* > *3*, 483 > “Movie of the structural changes during a catalytic cycle of nucleoside > monophosphate kinases” > *http://portal.uni-freiburg.de/structbio/structuregallery/ak_folder/mpeg* > in particular look at: > "*video as MPEG white background, closing & opening enzyme (707kb*)" > Each "black dot" [upper left, in the morph] indicates an observed crystal > structure. > > (2) *Lac repressor*: see *Proteopedia* page on lac repressor, > morphing from the structure bound to its cognate DNA, to that of the > structure bound to its the non-cognate DNA, > at:* http://proteopedia.org/w/Lac_repressor* > > best regards, > Joel > * > > * > > On 10 Feb 2012, at 22:51, Jacob Keller wrote: > > Interesting to juxtapose these two responses: > > James Stroud: > > How could they not be snapshots of conformations adopted in solution? > > > David Schuller: > > How could that possibly be the case when any structure is an average of all > > the unit cells of the crystal over the timespan of the diffraction > > experiment? > > > JPK > > > > ******************************************* > Jacob Pearson Keller > Northwestern University > Medical Scientist Training Program > email: j-kell...@northwestern.edu > ******************************************* > > > >
