Y box-binding protein-1 binds preferentially to single-stranded nucleic acids and exhibits 3′→5′ exonuclease activity

AUTOR(ES)

Izumi, Hiroto

FONTE

Oxford University Press

RESUMO

We have previously shown that Y box-binding protein-1 (YB-1) binds preferentially to cisplatin-modified Y box sequences. Based on structural and biochemical data, we predicted that this protein binds single-stranded nucleic acids. In the present study we confirmed the prediction and also discovered some unexpected functional features of YB-1. We found that the cold shock domain of the protein is necessary but not sufficient for double-stranded DNA binding while the C-tail domain interacts with both single-stranded DNA and RNA independently of the cold shock domain. In an in vitro translation system the C-tail domain of the protein inhibited translation but the cold shock domain did not. Both in vitro pull-down and in vivo co-immunoprecipitation assays revealed that YB-1 can form a homodimer. Deletion analysis mapped the C-tail domain of the protein as the region of homodimerization. We also characterized an intrinsic 3′→5′ DNA exonuclease activity of the protein. The region between residues 51 and 205 of its 324-amino acid extent is required for full exonuclease activity. Our findings suggest that YB-1 functions in regulating DNA/RNA transactions and that these actions involve different domains.

Documentos Relacionados

• Murine protein which binds preferentially to oligo-C-rich single-stranded nucleic acids.
• Solution structure of the single-stranded DNA binding protein of the filamentous Pseudomonas phage Pf3: similarity to other proteins binding to single-stranded nucleic acids.
• U1 RNA-protein complex preferentially binds to both 5' and 3' splice junction sequences in RNA or single-stranded DNA.
• Visualization and characterization of tobacco mosaic virus movement protein binding to single-stranded nucleic acids.
• Binding of RecA protein to single-stranded nucleic acids: spectroscopic studies using fluorescent polynucleotides.