Dear Kumar Could you please provide some information on your refinement protocol/progress and quality of your partial model thus far. Also, what is the quality and completeness of your data, in particular in the lowest resolution to 10 angs range. In this way one might be able to provide more concrete feedback. Experience from several structures around such resolution tells me that it is very much worth spending time optimizing what you can reliably fit and refine. This approach will pay off handsomely in terms of map quality and might lead to modeling what now may seem uninterpretable. The latest Phenix and Refmac versions are great, and their B-sharpening protocols can reveal a lot. In addition Buster with its handling of missing domains in Fc can also help a lot. Did you try any phase improvement by density modification? No. of molecules in asu? Also getting some experimental phase info (even at low resolution) might also help.
Best regards Savvas On 08 Dec 2011, at 07:47, atul kumar <atulsingh21...@gmail.com> wrote: > Dear all > > I have crytals which diffract up to 3.2 A at synchrotron, I am solving this > by molecular replacement. I have built 70% of the model successfully,but the > problem is it have a very poor density for some 30-40 residues at N terminal. > I can't build anything in this region,this could be because of disordered > structure or because of low resolution.what are the things which I can try to > improve this? > > suggestion are requested! > > thanks > regards' > Atul Kumar >
