[ccp4bb] P4132 vs. F23

Hi, All, we got many datasets from crystals of our protein. when the crystal has high quality, it will be indexed as F23 (correct space group). While diffracting poorer, it will be indexed as incorrect space group P4132. The crystals are twined. My question is: Given twinning, why the correct

[ccp4bb] Pseudo-symmetry/refinement

Hi all, The data is 2.2A, p41212, unit cell has c axis twice longer than a or b. Data processed by HKL2000, the diffraction pattern shows Strong-weak-weak in C direction, indicating translational pseudo-symmetry. Xtriage analysis confirmed the pseudo-symmetry (large Patterson off-origin pe

[ccp4bb] advices

Hello, all, My crystal grows very fast even though the protein conc. is now 1.5 mg/ml. The shape of the crystal likes a ruler plate with one side very thin. The crystal quality has diffraction to about 3.5A in a home source of 1.2 KW sealed tube Angilent equipment. But the data can not be inde

[ccp4bb] Crystallization buffer pH optimization

Hello, Shameful and sorry for asking this simple question, it looks like this when first starting a new setup in so-called structural biology. I remmeber a book of, probably, Hampton, in which there are tables of pH optimization for many buffers. For example for buffer TRIS, the table will l

[ccp4bb] ion in refinement

Hi, Everybody, For refinement of ion in my structure, I used phenix.metal_coordination to produce a geometry restraints file elbow.edits. But after including the file in the phenix refinement, the refined pdb has clash between metal and one of the coordinated atoms, as shown in the attachment.

[ccp4bb] seeking help from a bioinformatics guru

Hi, all, Would anybody help me out there? I'd like to got the statistics about: 1, How many unique transmemberane protein structure have by far been solved by X-ray? 2, How many X-ray structures of water-soluble domains in which their membrane-anchoring alpha helices have been removed? I trie

[ccp4bb] shipping dewar case

Hi, Everyone, Anybody knows where to buy a shipping dewar case (holder) or this is made by custom? Thanks Mike

[ccp4bb] STRAP secondary structure

Hello, Every one, I am preparing a ppt presentation in an emergency style. What I want is a graph of sequence alignment with secondary structure on the top. Using STRAP i can got alignment nicely, but did not know the tips to add secondary structure on top. Anybody of experienced can give me a