Re: [ccp4bb] Histogram matching in DM - question

2009-08-19 Thread Adam Ben-Shem
Hi Peter, You can specify in DM the mean density of the protein region in the SOLC keyword. However I am not sure this will affect the density distribution used for histogram matching. All the best, Adam.

Re: [ccp4bb] Histogram matching in DM - question

2009-08-19 Thread Clemens Vonrhein
And to add another small item: the SOLOMON interface in SHARP allows adjustment of the mean density depending on protein, DNA or RNA content. See http://www.globalphasing.com/sharp/manual/denmod2.html#MeanDensity Cheers Clemens On Wed, Aug 19, 2009 at 09:26:34AM +0100, Gerard Bricogne wrote:

Re: [ccp4bb] Histogram matching in DM - question

2009-08-19 Thread Gerard Bricogne
Dear Ed, The question of dealing appropriately with density modification in the presence of "heavy atoms" has been discussed in the paper on SHARP 2.0 (see Acta D59, 2023-2030, published in 2003) and the solution described in that paper has been available in all versions of SHARP/autoSHARP si

Re: [ccp4bb] Histogram matching in DM - question

2009-08-18 Thread Edward A. Berry
Peter Grey wrote: Hi everyone, I am trying to use density modification at rather low resolution (4-5A ) for an RNA structure. My first time ever with RNA. I usually use Histogram matching as part of the density modification scheme in DM. But this method is based on density distribution of pro

Re: [ccp4bb] Histogram matching in DM - question

2009-08-18 Thread Poul Nissen
Hi Peter, Histogram matching works well for RNA structure, but be aware that density modification in general can be very tricky at low resolution. If by any means you can exploit averaging, e.g. multicrystal averaging of non-isomorphous crystals, it will probably be very helpful. It will

[ccp4bb] Histogram matching in DM - question

2009-08-18 Thread Peter Grey
Hi everyone, I am trying to use density modification at rather low resolution (4-5A ) for an RNA structure. My first time ever with RNA. I usually use Histogram matching as part of the density modification scheme in DM. But this method is based on density distribution of protein maps I think. Is h