Structure of a rare non-standard sequence k-turn bound by L7Ae protein

Nucleic Acids Res. 2014 Apr;42(7):4734-40. doi: 10.1093/nar/gku087. Epub 2014 Jan 29.

Abstract

Kt-23 from Thelohania solenopsae is a rare RNA kink turn (k-turn) where an adenine replaces the normal guanine at the 2n position. L7Ae is a member of a strongly conserved family of proteins that bind a range of k-turn structures in the ribosome, box C/D and H/ACA small nucleolar RNAs and U4 small nuclear RNA. We have solved the crystal structure of T. solenopsae Kt-23 RNA bound to Archeoglobus fulgidus L7Ae protein at a resolution of 2.95 Å. The protein binds in the major groove displayed on the outer face of the k-turn, in a manner similar to complexes with standard k-turn structures. The k-turn adopts a standard N3 class conformation, with a single hydrogen bond from A2b N6 to A2n N3. This contrasts with the structure of the same sequence located in the SAM-I riboswitch, where it adopts an N1 structure, showing the inherent plasticity of k-turn structure. This potentially can affect any tertiary interactions in which the RNA participates.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Archaeal Proteins / chemistry*
  • Archaeoglobus fulgidus
  • Base Sequence
  • Hydrogen Bonding
  • Models, Molecular
  • Nucleic Acid Conformation
  • RNA / chemistry*
  • RNA-Binding Proteins / chemistry*

Substances

  • Archaeal Proteins
  • RNA-Binding Proteins
  • RNA

Associated data

  • PDB/4C4W