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Title: Direct-methods structure determination of a trypanosome RNA-editing substrate fragment with translational pseudosymmetry

Using direct methods starting from random phases, the crystal structure of a 32-base-pair RNA (675 non-H RNA atoms in the asymmetric unit) was determined using only the native diffraction data (resolution limit 1.05 Å) and the computer program SIR2014. The almost three helical turns of the RNA in the asymmetric unit introduced partial or imperfect translational pseudosymmetry (TPS) that modulated the intensities when averaged by the lMiller indices but still escaped automated detection. Almost six times as many random phase sets had to be tested on average to reach a correct structure compared with a similar-sized RNA hairpin (27 nucleotides, 580 non-H RNA atoms) without TPS. Lastly, more sensitive methods are needed for the automated detection of partial TPS.
  1. Univ. of Oklahoma, Oklahoma City, OK (United States). Health Sciences Center, Dept. of Biochemistry and Molecular Biology
Publication Date:
Grant/Contract Number:
P20 GM103640
Accepted Manuscript
Journal Name:
Acta Crystallographica. Section D. Structural Biology
Additional Journal Information:
Journal Volume: 72; Journal Issue: 4; Journal ID: ISSN 2059-7983
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE; National Institutes of Health (NIH)
Country of Publication:
United States
59 BASIC BIOLOGICAL SCIENCES; RNA structure determination; Patterson analysis; helical symmetry; ab initio phasing; noncrystallographic symmetry
OSTI Identifier: