Scientific article
Open access

Structural basis for polyadenosine-RNA binding by Nab2 Zn fingers and its function in mRNA nuclear export

Published inStructure, vol. 20, no. 6, p. 1007-1018
Publication date2012

Polyadenylation regulation and efficient nuclear export of mature mRNPs both require the polyadenosine-RNA-binding protein, Nab2, which contains seven CCCH Zn fingers. We describe here the solution structure of fingers 5-7, which are necessary and sufficient for high-affinity polyadenosine-RNA binding, and identify key residues involved. These Zn fingers form a single structural unit. Structural coherence is lost in the RNA-binding compromised Nab2-C437S mutant, which also suppresses the rat8-2 allele of RNA helicase Dbp5. Structure-guided Nab2 variants indicate that dbp5(rat8-2) suppression is more closely linked to hyperadenylation and suppression of mutant alleles of the nuclear RNA export adaptor, Yra1, than to affinity for polyadenosine-RNA. These results indicate that, in addition to modulating polyA tail length, Nab2 has an unanticipated function associated with generating export-competent mRNPs, and that changes within fingers 5-7 lead to suboptimal assembly of mRNP export complexes that are more easily disassembled by Dbp5 upon reaching the cytoplasm.

  • Active Transport, Cell Nucleus
  • Adenosine/chemistry
  • Amino Acid Sequence
  • Amino Acid Substitution
  • Conserved Sequence
  • Models, Molecular
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Nuclear Magnetic Resonance, Biomolecular
  • Nucleocytoplasmic Transport Proteins/chemistry/genetics/metabolism
  • Polymers/chemistry
  • Protein Binding
  • Protein Structure, Tertiary
  • RNA Transport
  • RNA, Messenger/chemistry
  • RNA-Binding Proteins/chemistry/genetics/metabolism
  • Saccharomyces cerevisiae/genetics/growth & development
  • Saccharomyces cerevisiae Proteins/chemistry/genetics/metabolism
  • Surface Properties
  • Thermodynamics
  • Zinc Fingers
Research group
Citation (ISO format)
BROCKMANN, Christoph et al. Structural basis for polyadenosine-RNA binding by Nab2 Zn fingers and its function in mRNA nuclear export. In: Structure, 2012, vol. 20, n° 6, p. 1007–1018. doi: 10.1016/j.str.2012.03.011
Main files (1)
Article (Published version)
ISSN of the journal0969-2126

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