[3dem] GroEL best resolution map. (FSC RESOLUTION ??)

[Marin van Heel]

Dear Natesh,

I just checked the technical data of the EMD-3407 dataset and I saw that 
its pixel size is 1.05A . That means that no resolution levels better 
than 3 x 1.05A = 3.15A  may be claimed for processing results based on 
that data set, following the standards we set in the past (for the 
younger generation: I am the main inventor of the FSC ;) ). Going beyond 
a resolution claim of 3.15A would mean that the dataset is undersampled, 
and would thus require a new data collection with a smaller pixel size. 
For a possible resolution claim of, say, 2A  you need a maximum pixel 
size of 0.66A !  Moreover, the 0.143 threshold FSC threshold used in 
this EMD-3407 case is itself wrong, while based on sloppy statistics. 
(https://www.biorxiv.org/content/early/2017/11/24/224402).Bottom line:  
to compare the results of different cryo-EM experiments you need correct 
resolution criteria applied to sufficiently fine sampled cryo-EM data.

Cheers

Marin

On 01/09/2018 12:57, Natesh Ramanathan wrote:
> Dear All,
>
>       Does anyone know/have a GroEL cryoEM map with resolution  2.5 Å 
> or better?
> I see that the best resolution in EMDataBank is 3.26 Å - EMD-3407 and 
> EMD-3415.
>       If you have one, is it possible to share the map with me?
>
> Many thanks.
> Best regards,
> Natesh
> -- 
> ----------------------------------------------------------
> "Live Simply and do Serious Things .. "
> - Dorothy Mary Crowfoot Hodgkin OM, FRS
>
> "In Science truth always wins"
> - Max Ferdinand Perutz OM FRS
> ----------------------------------------------------------
> Dr. Ramanathan Natesh
> Assistant Professor,
> School of Biology,
> Indian Institute of Science Education and Research Thiruvananthapuram 
> (IISER-TVM),
> Maruthamala P.O., Vithura,
> Thiruvananthapuram,  695551, Kerala, India
>
> natesh at iisertvm.ac.in <mailto:natesh at iisertvm.ac.in>
> http://www.researcherid.com/rid/C-4488-2008
> ORCID: http://orcid.org/0000-0002-1145-5962
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>
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>
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     Prof Dr Ir Marin van Heel

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