On 06/08/2011 07:19 PM, Shiva Bhowmik wrote:
Dear All,
I am working on a protein structure that yielded comparable diffraction
quality crystals from two different crystallization condition. One of the
crystallization condition conatins high conc. of salt pptant whereas the
oher one contains high conc. of organic pptant. There are some minor
differences in the stucture with respect to the backbone but what most
surprising is the oligomeric structure. AnSEC study suggest the protein to
be a tetramer in solution and a tetrameric assembly is observed in the
asymmetric unit of the space group of the crystal obtained from high conc.
of organic pptant. However, the crystal structure from the high conc. of
salt pptant does not reveal any oligomeric assembly - symmetry operations of
the space group does not suggest any oligomeric assembly. I believe the high
salt conc. disrupted the tetrameric assembly and enabled crystallization of
the protein as a monomer.
Curious to know if there has been any similar precedence before.
Cheers,
Shiva
I would submit both structures to PISA at the EBI, and look at the
interfaces to see if there is any similarity between the 2 forms..
Eleanor
