<div dir="ltr"><div class="gmail_default" style="font-size:small"><div class="gmail_default"><font face="arial, helvetica, sans-serif" color="#000000">I collected two datasets of the same ligand bound structure at 2.4 and 2.1 Å resolution. The apo structure has already been solved to 2.2Å resolution in P31 (and P3121 for SeMet). After processing each dataset as both P31 and P3121 in MOSFLM, I proceeded with MR with Phaser using sequential partial search models to place either 3 copies in the ASU for P3121, or 6 copies for P31. (The previously solved apo structure had 6 copies of the same protein in the ASU). <br></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif" color="#000000">*** in summary two datasets, processed as both P31 or P3121 </font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif" color="#000000"><br></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif" color="#000000">After running xtriage for either .mtz, I get this warning about NCS:<br></font></div><div class="gmail_default"><p><font face="arial, helvetica, sans-serif" color="#000000"> Distance to origin : 56.728<br> Height relative to origin : 26.388 %<br></font></p><p><font face="arial, helvetica, sans-serif" color="#000000">Translational pseudo-symmetry is very likely present in these data. Be aware that this will change the intensity statistics and may impact subsequent analyses, and in practice may lead to higher R-factors in refinement.</font></p></div><div style="font-size:12.8000001907349px"><div class="gmail_default" style="font-size:small"><font face="arial, helvetica, sans-serif" color="#000000">Regardless, I can proceed with the MR using sequential partial search models to place either 3 copies (P3121) or 6 copies (P31) with decent solutions (i.e. packing looks good upon inspection, scoring looks appropriate -> SOLU SET RFZ=2.8 TFZ=8.3 PAK=13<b>LLG</b>=-37 <b>LLG</b>=2199 as an example). However, I did get the following somewhat expected warnings:</font></div><div class="gmail_default" style="font-size:small"><font face="arial, helvetica, sans-serif" color="#000000"><br></font></div><div class="gmail_default" style="font-size:small"><font face="arial, helvetica, sans-serif" color="#000000">Number of known components (1) not divisible by 2: Translational <b>NCS</b> correction not applied<br>Large non-origin Patterson peak indicates that translational <b>NCS</b> is present</font></div><div class="gmail_default" style="font-size:small"><font face="arial, helvetica, sans-serif" color="#000000"><br></font></div><div class="gmail_default" style="font-size:small"><font face="arial, helvetica, sans-serif" color="#000000">Upon any attempt at initial refinement (with a number of different strategies), the R-factors are hung up > 0.42 (for example in the P3121, 2.1Å case): </font><span style="color:rgb(0,0,0);font-family:arial,helvetica,sans-serif">Start R-work = 0.4966, R-free = 0.5133; </span><span style="color:rgb(0,0,0);font-family:arial,helvetica,sans-serif">Final R-work = 0.4231, R-free = 0.4477</span></div><div class="gmail_default" style="font-size:small"><font face="arial, helvetica, sans-serif" color="#000000"><br></font></div><div class="gmail_default" style="font-size:small"><font face="arial, helvetica, sans-serif" color="#000000">My concern is that there is some pathology that is not being recognized (merohedral twinning) or that the NCS/pseudosymmetry is not being addressed appropriately. </font></div></div></div><div><font face="arial, helvetica, sans-serif" color="#000000"><br></font></div><font face="arial, helvetica, sans-serif" color="#000000">-- <br></font><div class="gmail_signature"><div dir="ltr"><font face="arial, helvetica, sans-serif" color="#000000"> Cheers,<br> John</font><br></div></div>
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