Subsets of the zinc finger motifs in dsRBP-ZFa can bind double-stranded RNA

Biochemistry. 1999 Mar 30;38(13):4001-7. doi: 10.1021/bi9825293.

Abstract

dsRBP-ZFa is a Xenopus zinc finger protein that binds dsRNA and RNA-DNA hybrids with high affinity and in a sequence-independent manner. The protein consists of a basic N-terminal region with seven C2H2 zinc finger motifs and an acidic C-terminal region that is not required for binding. The last four zinc finger motifs, and the linkers that join them, are nearly identical repeats, while the first three motifs and their linkers are each unique. To identify which regions of the protein are involved in nucleic acid binding, we examined the ability of five protein fragments to bind dsRNA and RNA-DNA hybrids. Our studies reveal that a fragment encompassing the three N-terminal, unique zinc finger motifs and another encompassing the last three of the nearly identical motifs have binding properties similar to the full-length protein. Since these two fragments do not share zinc finger motifs of the same sequence, dsRBP-ZFa must contain more than one type of zinc finger motif capable of binding dsRNA. As with the full-length protein, ssRNA and DNA do not significantly compete for dsRNA binding by the fragments.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding, Competitive / genetics
  • Cloning, Molecular
  • DNA-Binding Proteins*
  • Electrophoresis, Polyacrylamide Gel
  • Genetic Vectors / chemical synthesis
  • Molecular Sequence Data
  • Peptide Fragments / biosynthesis
  • Peptide Fragments / chemistry
  • Peptide Fragments / genetics
  • Peptide Fragments / metabolism*
  • Protein Binding / genetics
  • Protein Structure, Secondary
  • RNA, Double-Stranded / metabolism*
  • RNA-Binding Proteins / biosynthesis
  • RNA-Binding Proteins / chemistry
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • Recombinant Proteins / biosynthesis
  • Substrate Specificity / genetics
  • Xenopus
  • Xenopus Proteins*
  • Zinc Fingers* / genetics

Substances

  • DNA-Binding Proteins
  • Peptide Fragments
  • RNA, Double-Stranded
  • RNA-Binding Proteins
  • Recombinant Proteins
  • Xenopus Proteins
  • dsRBP-ZFa protein, Xenopus