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

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
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!

Von: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] Im Auftrag von Liu 
Gesendet: Mittwoch, 12. Oktober 2016 08:55
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

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