A tyrosyl-tRNA synthetase recognizes a conserved tRNA-like structural motif in the group I intron catalytic core

Cell. 1996 Dec 13;87(6):1135-45. doi: 10.1016/s0092-8674(00)81807-3.

Abstract

The Neurospora crassa mitochondrial (mt) tyrosyl-tRNA synthetase (CYT-18 protein) functions in splicing group I introns, in addition to aminoacylating tRNA(Tyr). Here, we compared the CYT-18 binding sites in the N. crassa mt LSU and ND1 introns with that in N. crassa mt tRNA(Tyr) by constructing three-dimensional models based on chemical modification and RNA footprinting data. Remarkably, superimposition of the CYT-18 binding sites in the model structures revealed an extended three-dimensional overlap between the tRNA and the group I intron catalytic core. Our results provide insight into how an RNA-splicing factor can evolve from a cellular RNA-binding protein. Further, the structural similarities between group I introns and tRNAs are consistent with an evolutionary relationship and suggest a general mechanism for the evolution of complex catalytic RNAs.

Publication types

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

MeSH terms

  • Base Sequence
  • Binding Sites / genetics
  • Biological Evolution
  • Conserved Sequence
  • Introns*
  • Molecular Sequence Data
  • Neurospora crassa
  • Nucleic Acid Conformation
  • Protein Conformation
  • Protein Structure, Tertiary
  • RNA Splicing / physiology
  • RNA, Fungal / chemistry
  • RNA, Fungal / metabolism
  • RNA, Fungal / physiology
  • RNA, Transfer, Tyr / chemistry
  • Tyrosine-tRNA Ligase / chemistry*
  • Tyrosine-tRNA Ligase / genetics*
  • Tyrosine-tRNA Ligase / metabolism

Substances

  • RNA, Fungal
  • RNA, Transfer, Tyr
  • Tyrosine-tRNA Ligase