1. Structural basis of pre-let-7 miRNA recognition by the zinc knuckles of pluripotency factor Lin28.
- Author
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Loughlin FE, Gebert LF, Towbin H, Brunschweiger A, Hall J, and Allain FH
- Subjects
- Base Sequence, Binding Sites genetics, Binding, Competitive, Calorimetry, Cell Line, Tumor, HeLa Cells, Humans, Magnetic Resonance Spectroscopy, MicroRNAs genetics, MicroRNAs metabolism, Models, Molecular, Molecular Sequence Data, Mutation, Nucleotide Motifs genetics, Oligoribonucleotides chemistry, Oligoribonucleotides genetics, Oligoribonucleotides metabolism, Protein Binding, RNA-Binding Proteins genetics, RNA-Binding Proteins metabolism, Sequence Homology, Nucleic Acid, MicroRNAs chemistry, Nucleic Acid Conformation, Protein Structure, Tertiary, RNA-Binding Proteins chemistry
- Abstract
Lin28 inhibits the biogenesis of let-7 miRNAs through a direct interaction with the terminal loop of pre-let-7. This interaction requires the zinc-knuckle domains of Lin28. We show that the zinc knuckle domains of Lin28 are sufficient to provide binding selectivity for pre-let-7 miRNAs and present the NMR structure of human Lin28 zinc knuckles bound to the short sequence 5'-AGGAGAU-3'. The structure reveals that each zinc knuckle recognizes an AG dinucleotide separated by a single nucleotide spacer. This defines a new 5'-NGNNG-3' consensus motif that explains how Lin28 selectively recognizes pre-let-7 family members. Binding assays in cell lysates and functional assays in cultured cells demonstrate that the interactions observed in the solution structure also occur between the full-length protein and members of the pre-let-7 family. The consensus sequence explains several seemingly disparate previously published observations on the binding properties of Lin28.
- Published
- 2011
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