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

Hiroto Izumi, Toshihiro Imamura, Gunji Nagatani, Tomoko Ise, Tadashi Murakami, Hidetaka Uramoto, Takayuki Torigoe, Hiroshi Ishiguchi, Yoichiro Yoshida, Minoru Nomoto, Tatsuro Okamoto, Takeshi Uchiumi, Michihiko Kuwano, Keiko Funa, Kimitoshi Kohno

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Abstract

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.

Original languageEnglish
Pages (from-to)1200-1207
Number of pages8
JournalNucleic acids research
Volume29
Issue number5
Publication statusPublished - Mar 1 2001

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All Science Journal Classification (ASJC) codes

  • Genetics

Cite this

Izumi, H., Imamura, T., Nagatani, G., Ise, T., Murakami, T., Uramoto, H., ... Kohno, K. (2001). Y box-binding protein-1 binds preferentially to single-stranded nucleic acids and exhibits 3′→5′ exonuclease activity. Nucleic acids research, 29(5), 1200-1207.