I had a structure that was done with crystals that were about a year old. Initial crystals appeared in a less then a day and diffracted very poorly. In trying to make room for more trays I reexamined the old trays before throwing them out and low and behold nice well diffracting crystals. Of course these are probably more the exception then the rule.

Len


Leonard Thomas Ph. D.
Macromolecular Crystallography Laboratory Manager
University of Oklahoma
Department of Chemistry and Biochemistry
620 Parrington Oval
Norman, OK 73032

lmtho...@ou.edu
Office: 405-325-1126
Lab: 405-325-7571

On Feb 5, 2009, at 2:05 PM, Nathaniel Echols wrote:

Here's another very similar case:

http://www.ncbi.nlm.nih.gov/pubmed/12270703

On Thu, Feb 5, 2009 at 11:48 AM, William G. Scott <wgsc...@chemistry.ucsc.edu > wrote:
Some things improve with age. Here is one of my favorite stories:



http://tinyurl.com/oldtrna


The crystal structure of yeast phenylalanine tRNA at 2.0 Å resolution: cleavage by Mg2+ in 15-year old crystals

Luca Jovine,  Snezana Djordjevica and Daniela Rhodes

We have re-determined the crystal structure of yeast tRNAPhe to 2.0 Å resolution using 15 year old crystals. The accuracy of the new structure, due both to higher resolution data and formerly unavailable refinement methods, consolidates the previous structural information, but also reveals novel details. In particular, the water structure around the tightly bound Mg2+ is now clearly resolved, and hence provides more accurate information on the geometry of the magnesium-binding sites and the role of water molecules in coordinating the metal ions to the tRNA. We have assigned a total of ten magnesium ions and identified a partly conserved geometry for high-affinity Mg2+ binding. In the electron density map there is also clear density for a spermine molecule binding in the major groove of the TΨC arm and also contacting a symmetry-related tRNA molecule. Interestingly, we have also found that two specific regions of the tRNA in the crystals are partially cleaved. The sites of hydrolysis are within the D and anticodon loops in the vicinity of Mg2+.








On Feb 5, 2009, at 11:11 AM, Edward Snell wrote:

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Dear All,

I was recently trying to find references on how age may degrade a
crystal, i.e. grow them and use them or preserve them as fresh as
possible. I seem to remember seeing a couple of papers on this but my
memory is fading and I have been unable to locate them. Can anyone jog
my memory or tell me if I'm imagining things? I've found plenty on the
protein prep etc. but nothing on the crystal.

Thanks,

Eddie.


Edward Snell Ph.D.
Assistant Prof. Department of Structural Biology, SUNY Buffalo,
Hauptman-Woodward Medical Research Institute
700 Ellicott Street, Buffalo, NY 14203-1102
Phone:     (716) 898 8631         Fax: (716) 898 8660
Email: esn...@hwi.buffalo.edu  Telepathy: 42.2 GHz

Heisenberg was probably here!    Crystallization, how quaint!

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