Dear Julian,
RELION cannot do this. Sriram should have software that does this, but I'm
not sure whether it is available.
HTH,
Sjors
> Dear Julian,
> The approach of using images recorded in a tilt series for 3D
> reconstruction using a single-particle cryo-EM approach is described in
> this paper.
>
> Bartesaghi A, Lecumberry F, Sapiro G, Subramaniam S:
> Protein secondary structure determination by constrained single-particle
> cryo-electron tomography.
> Structure 2012, 20(12):2003-2013.
>
> Sriram
>
> On 4/26/17, 10:13 AM, "Julian Reitz" <[log in to unmask]> wrote:
>
> Dear all,
>
> I would like to give you a short description of what I want to do, so
> that you can understand my problems and hopefully help me to find a
> solution.
>
> We are currently working on some cryoET data. The standard pipeline
> therefore would be to reconstruct the tomogram, find particles in the
> tomogram and make sub-tomogram averaging.
> However our current tilt-series are difficult to align and due to the
> poor alignment we have a non optimal reconstruction and therefore also
> not the best resolution in the sub-tomogram averaging.
>
> Our idea now was as follows:
> First use the normal workflow. We then used the 3D coordinates of the
> particles in the tomogram to calculate back, where the projections of
> these particles are on the images of the tilt-series. We now wanted to
> use these information to proceed in a single-particle-like way in
> order to circumvent the problems with the alignment. Of course the
> particles we extract from the images in this way are not independent
> from each other, since we know the difference of the tilt angle from
> image to image. Is there a way to make use of these information with
> relion? I just tried to make a 3D-refinement (we have a very good
> starting model) but the result doesn't look good and I can see from
> the output star file that the orientations are not correct.
>
> Any ideas?
>
> Best,
> Julian
>
>
>
--
Sjors Scheres
MRC Laboratory of Molecular Biology
Francis Crick Avenue, Cambridge Biomedical Campus
Cambridge CB2 0QH, U.K.
tel: +44 (0)1223 267061
http://www2.mrc-lmb.cam.ac.uk/groups/scheres
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