Recognition of eIF4G by rotavirus NSP3 reveals a basis for mRNA circularization

Mol Cell. 2002 Jun;9(6):1273-83. doi: 10.1016/s1097-2765(02)00555-5.

Abstract

Rotaviruses, segmented double-stranded RNA viruses, co-opt the eukaryotic translation machinery with the aid of nonstructural protein 3 (NSP3), a rotaviral functional homolog of the cellular poly(A) binding protein (PABP). NSP3 binds to viral mRNA 3' consensus sequences and circularizes mRNA via interactions with eIF4G. Here, we present the X-ray structure of the C-terminal domain of NSP3 (NSP3-C) recognizing a fragment of eIF4GI. Homodimerization of NSP3-C yields a symmetric, elongated, largely alpha-helical structure with two hydrophobic eIF4G binding pockets at the dimer interface. Site-directed mutagenesis and isothermal titration calorimetry documented that NSP3 and PABP use analogous eIF4G recognition strategies, despite marked differences in tertiary structure.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Dimerization
  • Eukaryotic Initiation Factor-4G
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Peptide Initiation Factors / chemistry*
  • Peptide Initiation Factors / metabolism
  • Protein Structure, Quaternary
  • RNA, Messenger / metabolism*
  • RNA-Binding Proteins / chemistry
  • RNA-Binding Proteins / metabolism
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Sequence Alignment
  • Viral Nonstructural Proteins / chemistry*
  • Viral Nonstructural Proteins / metabolism

Substances

  • Carrier Proteins
  • Eukaryotic Initiation Factor-4G
  • NSP3 protein, Rotavirus
  • Peptide Initiation Factors
  • RNA, Messenger
  • RNA-Binding Proteins
  • Recombinant Fusion Proteins
  • Viral Nonstructural Proteins

Associated data

  • PDB/1LJ2