title: Human ribosomal protein L7 carries two nucleic acid-binding domains with distinct specificities.
abstract: Protein L7 is associated with the large subunit of eukaryotic ribosomes that can act as a co-regulator of nuclear receptor-mediated transcription. In this study we show that L7 carries in addition to the known N-terminal nucleic acid-binding domain (NBD 1) a second one (NBD 2) which maps to the 50 C-terminal amino acids of the protein. The amino acid sequence of this region does not contain any of the known nucleic acid binding motifs; thus, NBD 2 may represent a new class of nucleic acid-binding protein motifs. NBD 2 is conserved in all known eukaryotic L7 homologs, whereas NBD 1 is only present in mammalian L7. Binding studies show that NBD 2 is functionally different from NBD 1 in that it binds preferentially to 28S rRNA, suggesting that NBD 2 is involved in the attachment of protein L7 to the large ribosomal subunit. Potential functions of NBD 1 and NBD 2 in translational and nuclear receptor-mediated transcriptional control are discussed.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D017931:DNA Primers; D006801:Humans; D008969:Molecular Sequence Data; D012313:RNA / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid