Dear Nicolas, Thank you for your help. Our DNA is not a palindromic sequence, and I think it should not be degraded easily. The data can be processed in the space groups C2221, P41212 or lower, with 12bp, 6bp ,24bp or longer in one NCS. I can see the connection between two symmetric DNA molecules in all these space groups. Actually, I am really confused about that because 20pb-DNA was used in crystallization. Peng
在2018年01月30 16时58分, "Nicolas FOOS"<[email protected]>写道: Dear Peng, to me your problem sound a bit strange, except if it's a palindromic sequence. I don't understand how you can have one part of the DNA in one asymmetric unit and one in another one. My question are : maybe you considering a NCS as a true symmetry and underestimate the unit-cell dimensions? Or you DNA has been degraded by DNase and the current size is not 20pb, in this case you are not supposed to create an artificial connection. Is the resolution good enough to be certain of the sequence ? Sorry, I don't provide any answer, but I am curious and try to understand what is going on. Hope this finally help. Nicolas Nicolas Foos PhD Structural Biology Group European Synchrotron Radiation Facility (E.S.R.F) 71, avenue des Martyrs CS 40220 38043 GRENOBLE Cedex 9 +33 (0)6 76 88 14 87 +33 (0)4 76 88 45 19 On 29/01/2018 20:28, Peng wrote: Hello, everyone， Recently, we solve a protein-DNA complex. 20bp-DNA was used for crystallization, but only 6bp was found in one symmetric unit. My question is： How to define the DNA bond between P and O3’ from two different symmetric units during my refinement? Peng
