Just for clarity: symmetry mates have been taken into account, the dimer really doesn't show up in those crystals.
Seb. At Wednesday, 08-04-2015 on 15:16 Marjolein Thunnissen wrote: Hi I guess you mean that the protein is a monomer in the asymmetric unit. It is quite common for multimeric proteins to crystallise such that the full symmetric complex is formed by applying the crystallographic axis themselves. So you will need to check the crystallographic contacts to see whether your protein is an example of such a system. You can use the program PISA to do this: http://www.ebi.ac.uk/pdbe/pisa/ best regards Marjolein Thunnissen On 08 Apr 2015, at 15:07, Sebastiaan Werten wrote: Dear all, we are currently working on a protein that is known to exist in a monomer-dimer equilibrium. At the high concentrations used for crystallisation assays, the dimer is predominant and the monomer practically undetectable. Nevertheless, one of the crystal forms that we have obtained contains the monomeric species, not the dimer. I was wondering if anyone is aware of similar (published) cases, and if the phenomenon as such has been discussed in detail anywhere? I did literature searches but so far couldn't find anything. Any pointers would be much appreciated! Best wishes, Sebastiaan Werten. Dr. Marjolein Thunnissen Science Coordinator Structural Biology MAX IV Laboratory Lund University P.O. Box 118, SE-221 00 Lund, Sweden Visiting address: Ole Römers väg 1, 223 63 Lund Telephone: +46 766 32 04 17 www.maxlab.lu.se [1] Links: ------ [1] http://www.maxlab.lu.se/
