[3dem] [ccpem] Making 2D References from a 3D Refinement

[Marin van Heel]

Dear Austin

You may want to look at the strategies implemented in IMAGIC-4D for this 
purpose! (http://journals.iucr.org/m/issues/2017/05/00/kf5002/)

Cheers,

Marin


On 05/01/2018 17:36, Austin Dixon wrote:
> I have a pretty good 3D structure of a protein we are working on with a lot of heterogeneity in a certain section. I have used multiple refinements, masking, and refinements with finer angular sampling to get a structure that has most of the features we are looking for, but it represents a very small percentage of the particles originally picked, and is at >10 A resolution. I'd like to increase that number of particles/resolution by using this 3D consensus to make 2D references and then run that through autopicking. Hopefully that will net me more high quality particles that contain the subunits of interest.
>
> Is there a way to do this Relion? Chimera?
>
> Also, is this introducing bias in any way? The 2D classes would be generated from a 3D structure that was generated from the same raw data, so I wouldn't think so, but any advice on that would be great.
>
> Thanks!
> Austin Dixon
> Rockefeller University

-- 
==============================================================

     Prof Dr Ir Marin van Heel

     Laboratório Nacional de Nanotecnologia - LNNano
     CNPEM/LNNano, Campinas, Brazil

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     Emeritus Professor of Cryo-EM Data Processing
     Leiden University
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     Emeritus Professor of Structural Biology
     Imperial College London
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