2MEQ

Structure of Helix 69 from Escherichia coli 23S Ribosomal RNA

Summary for 2MEQ

• Entry DOI: 10.2210/pdb2meq/pdb
• NMR Information: BMRB: 18975
• Descriptor: RNA_(5'-R(P*GP*GP*CP*CP*GP*UP*AP*AP*CP*UP*AP*UP*AP*AP*CP*GP*GP*UP*C)-3') (1 entity in total)
• Functional Keywords: helix 69, ribosomal, rna
• Total number of polymer chains: 1
• Total formula weight: 6077.67

Authors

Jiang, J.,Aduri, R.,Chow, C.S.,Santalucia, J. (deposition date: 2013-09-26, release date: 2014-01-01, Last modification date: 2024-05-15)

Primary citation

Jiang, J.,Aduri, R.,Chow, C.S.,Santalucia, J.
Structure modulation of helix 69 from Escherichia coli 23S ribosomal RNA by pseudouridylations.
Nucleic Acids Res., 42:3971-3981, 2014

PubMed Abstract: Helix 69 (H69) is a 19-nt stem-loop region from the large subunit ribosomal RNA. Three pseudouridine (Ψ) modifications clustered in H69 are conserved across phylogeny and known to affect ribosome function. To explore the effects of Ψ on the conformations of Escherichia coli H69 in solution, nuclear magnetic resonance spectroscopy was used to reveal the structural differences between H69 with (ΨΨΨ) and without (UUU) Ψ modifications. Comparison of the two structures shows that H69 ΨΨΨ has the following unique features: (i) the loop region is closed by a Watson-Crick base pair between Ψ1911 and A1919, which is potentially reinforced by interactions involving Ψ1911N1H and (ii) Ψ modifications at loop residues 1915 and 1917 promote base stacking from Ψ1915 to A1918. In contrast, the H69 UUU loop region, which lacks Ψ modifications, is less organized. Structure modulation by Ψ leads to alteration in conformational behavior of the 5' half of the H69 loop region, observed as broadening of C1914 non-exchangeable base proton resonances in the H69 ΨΨΨ nuclear magnetic resonance spectra, and plays an important biological role in establishing the ribosomal intersubunit bridge B2a and mediating translational fidelity.

PubMed: 24371282
DOI: 10.1093/nar/gkt1329

Experimental method

SOLUTION NMR