Dear Pascal, I'm assuming that you're talking about using the negative stain image as an MR model. I don't recall hearing of this having ever worked (though I would be very interested of course if anyone has managed to do this!), but my intuition is that it's not going to work. Negative stain just gives you an external shape, whereas a cryo-EM reconstruction has internal features as well.
Presumably you don't have atomic models of the individual components of the complex? If you did, using those directly for MR would be my first choice, but you could also consider making a pseudo-atomic model by docking them into the shape of the negative stain image. Such a model would add substantial higher-resolution information. Best wishes and good luck, Randy Read > On 25 Oct 2016, at 02:49, Pascal Egea <pas...@msg.ucsf.edu> wrote: > > Dear All, > > I would like to know if it is possible to use a low resolution EM > reconstruction of a complex obtained in negative stain EM (not cryo EM) to > help molecular replacement in a 4.5A resolution X-ray diffraction data set of > the same complex > I am aware of the possibility of using low resolution cryoEM maps for MR as > described in the review from Jackson et al in Nature Protocols but I was > wondering if there is an intrinsically impossibility for negative stain > reconstructions. > > Any thoughts or advice will be greatly appreciated. > > Best, > > -- > Pascal F. Egea, PhD > Assistant Professor > UCLA, David Geffen School of Medicine > Department of Biological Chemistry > Boyer Hall room 356 > 611 Charles E Young Drive East > Los Angeles CA 90095 > office (310)-983-3515 > lab (310)-983-3516 > email pegea at mednet.ucla.edu <http://mednet.ucla.edu/> ------ Randy J. Read Department of Haematology, University of Cambridge Cambridge Institute for Medical Research Tel: + 44 1223 336500 Wellcome Trust/MRC Building Fax: + 44 1223 336827 Hills Road E-mail: rj...@cam.ac.uk Cambridge CB2 0XY, U.K. www-structmed.cimr.cam.ac.uk
