[3dem] 3dem Digest, Vol 79, Issue 11

Tapu Shaikh shaikh at ceitec.muni.cz
Wed Mar 12 14:29:45 PDT 2014


On 03/12/2014 10:07 PM, Sindelar, Charles wrote:
> Hi Qiu-Xing, the experiment that Ed refers to is one of the better ones you can do- the FSC between the PDB-generated map, and your experimental map.  Particularly if you do only rigid-body fitting (not flexible fitting), the 0.5 cut-off will give you a conservative estimate of the resolution- i.e. it is difficult or impossible to over-estimate the resolution in this way.

I wrote to Qui-Xing off-list because I didn't know the math in detail, 
but Pawel had given a talk where he said that, when computing the 
cross-resolution between an atomic model and an EM map, a SNR of 1 
corresponds to a FSC of 1/sqrt(2) rather than 1/2. [Specifically, the 
math I didn't understand was the origin of the exponent 2 in 
SNR=FSC^2/(1-FSC^2).]  If that's the case, a 0.5 cutoff may not be such 
a conservative estimate.

-Tapu



More information about the 3dem mailing list