Well - it sounds hopeful but still challenging.. First suggestion - are you SURE the SG is C2221 and not C222? If your two molecules are related by a NC translation of x_tran, y_tran, 1/2 then you will get the apparent absences along the 0 0 l axis which suggest SG C 2221 but the true SG could be C 222.
If you have run pointless/aimless/ctruncate, the log file will tell you of any possible non-cryst translation. Next - I usually see if there are any anomalous peaks in a difference fourier. That is a very long shot but sometimes helps pin point S atoms and encourages you that the solution is partially correct Then I would try to do auto building with Buccaneer and see how far it gets - buccaneer tries to use NCS to improve the model . Try those ideas first then maybe invoke parrot to do NCS averaging.. Eleanor On 25 October 2016 at 13:16, Vikram Dalal <vikram.dalal...@gmail.com> wrote: > Hi everyone, > > We are trying to solve a protein structure of 2.6 A. We have processed it > with HKL2000. We have even tried processing with mosflm and xia2. It is in > C2221 space group (checked by pointless) and data is not twinned. It has > 31% identical with a search model and has 57% sequence coverage. There are > 2 subunits in asu. > > I did not get proper phases with MOLREP and phaser. I have tried Balbes (R > free 50) and Mr BUMP (R free 54).But, density from balbes look some > reasonable. > So i have refined it in ccp4i and phenix differently and then model build > it by coot. My protein has 377 Amino acid. But, I stucked at R free 41 and > now i have amino acid 50 to 369 in both chains, still 49 amino acid at N > terminal and 8 amino acid at C terminal are missing and some loops are > missing in between too. > > *I have tried the ARP/wARP, but it does not work for it. * > > *I have even tried phase and build of phenix but condition remain same. i > got stuck at R free at 42 and same around 49 amino acids at N terminal and > 8 amino acids at C terminal and some internal loops still absent.* > > *Thank you in advance.* > > > > > > >> >> >> >> >> >
