Specific ammonium ion requirement for functional ribosomal RNA tertiary structure

Biochemistry. 1993 Nov 23;32(46):12279-82. doi: 10.1021/bi00097a002.

Abstract

In compactly folded RNAs, coordination or hydrogen bonding of cations in specific sites is a potentially important aspect of the tertiary structure. NH4+ specifically stabilizes the tertiary structure of a conserved, 58-nt fragment of the large subunit ribosomal RNA, as judged in two ways: a melting transition associated with tertiary interactions is sharpened and stabilized more effectively by NH4+ than by any alkali metal cation, and the affinity of the RNA fragment for ribosomal protein L11 or the antibiotic thiostrepton is approximately 10-fold stronger when measured in NH4+ than in Na+. The dependence of the melting temperature on NH4+ concentration shows that a single bound ion is responsible for these effects. The requirement of different ribosome functions for NH4+ suggests that other such sites exist in ribosomal RNAs.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cations, Monovalent
  • Escherichia coli
  • Hydrogen Bonding
  • Magnesium / chemistry
  • Nucleic Acid Conformation
  • Protein Binding
  • Quaternary Ammonium Compounds / chemistry*
  • RNA, Ribosomal / chemistry*
  • Ribosomal Proteins / metabolism
  • Ribosomes / chemistry*
  • Temperature
  • Thiostrepton / metabolism

Substances

  • Cations, Monovalent
  • Quaternary Ammonium Compounds
  • RNA, Ribosomal
  • RNA, ribosomal, 26S
  • Ribosomal Proteins
  • ribosomal protein L11
  • Thiostrepton
  • Magnesium