Yujie, I would try using another processing program if you have it available, say Mosflm. I look at similar looking diffraction data recently, though without the salt crystals mixed in as Herman observed which you also need to take care of in the future, and HKL did not handle if very well, Mosflm was able to provide a usable data set. In fairness I have had the reverse occur also were Mosflm was unhappy with the data and HKL gave usable data.
Good Luck. Leonard M. Thomas Ph.D. Macromolecular Crystallography Laboratory Oklahoma COBRE in Structural Biology Price Family Foundation Institute of Structural Biology Department of Chemistry and Biochemistry University of Oklahoma Stephenson Life Sciences Research Center 101 Stephenson Parkway Norman, OK 73019 405-325-1126 lmtho...@ou.edu http://barlywine.chem.ou.edu http://structuralbiology.ou.edu ________________________________________ From: CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> on behalf of herman.schreu...@sanofi.com <herman.schreu...@sanofi.com> Sent: Wednesday, October 12, 2016 2:35:38 AM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] AW: strange X-ray diffraction diagram——RNA Or Complex？ Dear Yujie, You have salt crystals in your loop, as evidenced by some very strong reflections at high resolution. On the left, at nine o’clock, again at high resolution, you have a collection of spots that do not seem to fit to a single lattice. Since the low resolution region looks much cleaner, this might again be salt or some other small molecule that formed multiple micro crystals. However, the diffraction at low resolution looks like a bona fide macromolecular crystal (protein and/or RNA). What I would do is to apply a resolution cut-off and only use the low resolution data for indexing. Once you found a good indexing, you could process the data including the high resolution data as well. Good luck! Herman Von: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] Im Auftrag von Liu Rachel Gesendet: Mittwoch, 12. Oktober 2016 08:55 An: CCP4BB@JISCMAIL.AC.UK Betreff: [ccp4bb] strange X-ray diffraction diagram——RNA Or Complex？ Dear everyone: Recently, I suffered a problem during my research work. I purified a zinc finger protein, and crystallized as a beautiful cube in a reservoir solution only containing phosphate as the precipitant, no other buffer or molecules. However, regardless of multiple optimization, the crystal diffracted badly (7~8 Å best). I have also tried co-crystallization with dsRNA because this protein can bind to dsRNA. Then crystals grow in a new condition（2.5M (NH4)2SO4，0.1M BTP, pH7.0）and its form change to cluster of needle. But the X-ray diffraction diagram is very strange（as shown in the picture）. The Data cannot be processed with HKL2000 either. I want to figure out, could this be a RNA crystal rather than the complex? Or is there anybody know about the crystal of RNA molecular？ Thank you very much! Yujie Liu Room 2071, research center in life sciences, China Agricultural University No. 2 yuanmingyuan west road, Haidian District, Beijing, 100193 P.R. China Tel: (86)-10-62734078
