Journal of Biological Chemistry · 1998 · 81 citations · 23 references
Life SciencesGeneticsMolecular BiologyGene ExpressionNucleic Acid BiochemistryTranscriptionNucleic Acid-protein InteractionsProtein-nucleic Acid InteractionsRecombination ProteinsRna StructureRna-binding ProteinsRna-protein InteractionsDna-binding MotifsNucleic Acid Binding DomainsNucleic Acid Recognition MotifsNucleotide Binding DomainsNucleotide-binding MotifProtein Binding DomainsRna-binding DomainsSequence-specific Recognition
The B cell-specific, sequence-specific duplex DNA-binding protein LR1 is a transcriptional activator and may also function in heavy chain class switch recombination. LR1 is composed of two polypeptides, a 106-kDa subunit that is nucleolin, and a 45-kDa subunit that we now show to be a specific isoform of hnRNP D. hnRNP D and nucleolin both contain canonical RNA binding domains (RBDs also called RRMs) and Arg-Gly-Gly (RGG) motifs. Although these motifs are not commonly associated with sequence-specific recognition of duplex DNA, nonetheless LR1 binds duplex DNA with high affinity (KD = 1.8 nM) and clear sequence specificity. Two RBD-RGG proteins can therefore combine to produce a sequence-specific duplex DNA-binding protein.
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