So far, the native crystals diffracted best to 2.4A. The MAD data diffracted to 2.6~2.7A. We attempted to use phenix.hyss to identify copper atoms, and the program had hard time to identify the sites.
The protein: Cu ratio is around 1:1, which is decided by ICP-AES measurement of the crystallization sample, not derived from the number of peaks in the anomalous map. The crystal contains copper as a cofactor, not a soaking derivative thing. As to oligomerization, it could be dimer or trimer, however, we don't have a model for it, since we dont know exactly, how does the drug link the monomers. I used phaser to do the MR, basically, what I did was to search one copy each time, the top 20 solutions will be used to start the search of the next copy. It stuck after finding four copies, and, I tried to change the some paramters for searching, such as percentage for peaks, it did not help. I would love the hear from experienced people about some tricks using phaser to solve some difficult MR cases. thanks a lot Yi
