[ccp4bb]: Re: Time for CA-only models to be abolished ?

[<wgscott@chemistry.ucsc.edu>]

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>
>
> that's all nice and dandy, but:
>
> (a) what good is information that is unreliable and unverifiable ? is a
> CA-only model with tracing errors really of any use ? is it 
> (biological)
> signal or is it (biological) noise ?

Dear Gerard et al:

I signed your petition with as little hesitation as signing the one 
against attacking Iraq ( http://NoIraqAttack.org/ ), but I think Ed 
Berry has a reasonable point:  In the case of low-resolution structures 
such as the 70S ribosome and the Group I intron, for example, knowing 
the phosphate backbone fold of the RNA is very informative.  A 
phosphate backbone is easier to see than a polypeptide backbone, and is 
thus a bit more reliable, but the rule that the pdb should not accept 
backbone-only models should have an escape-clause for situations where 
this information is clearly of utility and represents the least-biased 
representation of the electron density.

Bill Scott