Question

Asked 7th Jun, 2018

The Chinese University of Hong Kong

Any suggestion on solving RNA Crystal structure?

Hi everyone, I am looking for advice on solving RNA structure. I collected one dataset which has a high resolution around 1.5 A in H3 space group.The RNA contains 23 nucleotides, I calculated the cell content, it suggested two strands in asymmetric unit. when I analyse the data by phenix Xtriage, it said that the data had translational NCS and may also have an NCS rotation axis parallel to a crystallographic axis. And it said that the data had a higher crystallographic symmetry (R32:H). So when I processed the data to R32 and recalculate the cell content, it suggests that 1 strand in asymmetric unit and still has translational NCS. I used a high sequence identity published structure as a search model to perform molecular replacement, it output a solution with high TFZ (26.8) and LLG, but when I open it in coot, the electrondensity doesn't fit well and did refinement, the R factors are very high, around 47-48%. So do you ever encounter such situation during solving the RNA structure? Look forward to your advice. Thank you.

Yan Wang

University of Texas Medical Branch at Galveston

Emm I don’t know whether you are still working on it,but personally if your r factor is such high,it might just because you did not find the right solution on MR.

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