Re: [ccp4bb] structure with missing density

2018-10-10 Thread Pavel Afonine
Hi Deepanshu, how complete the data set? What's completeness across resolution zones? Systematically missing reflections can have systematic impact in real space (maps). I've seen entire ligands or domains disappear due to missing low-resolution data. Just another check-point to consider.. Good

Re: [ccp4bb] structure with missing density

2018-10-09 Thread Ditlev Egeskov Brodersen
Dear Deepanshu, Is the primary sequence in the neighbourhood of your missing strands conserved? Perhaps that part differs in your structure relative to the search model. Have you tried omitting the region from MR and rerunning refinement without to see if some new density pops up? If not,

[ccp4bb] structure with missing density

2018-10-09 Thread Deepanshu Choudhary
Dear all, I am working on a protein complex. After many efforts, I obtained crystals from one of the refinement screen (which took few weeks to grow) and I got a 3 Å dataset at synchrotron. I scaled the dataset in P21 spacegroup (which is also confirmed by Zanuda and Pointless). There is no

Re: [ccp4bb] Structure with missing density

2018-03-09 Thread Liang Tong
Hello Rajesh We serendipitously encountered three cases where a contaminating fungus led to proteolysis of the proteins, which was required for their crystallization. We identified the fungus by sequencing a little bit of its genome, and found that it is Penicillium! Here are two of the

Re: [ccp4bb] Structure with missing density

2018-03-09 Thread Edward Snell
Subject: [ccp4bb] Structure with missing density Dear BB, I apologize for the off topic. But I strongly believe this is the right place to ask my question. We are working on a protein that is 300 amino acids in length. After many efforts, we could solve the structure at 1.60 Å resolution

Re: [ccp4bb] Structure with missing density

2018-03-09 Thread Thomas Cleveland
Hi, Long crystallization times and irreproducibility together with missing residues points strongly to some slow proteolysis in your crystal drops that eventually generated a crystallizable fragment. A lot of people actually do this on purpose by adding proteases to generate stable fragments.

[ccp4bb] Structure with missing density

2018-03-09 Thread Rajesh
Dear BB, I apologize for the off topic. But I strongly believe this is the right place to ask my question. We are working on a protein that is 300 amino acids in length. After many efforts, we could solve the structure at 1.60 Å resolution. It took almost 10 months to get this crystal and we