Ribosomal protein L7/L12 has a helix-turn-helix motif similar to that found in DNA-binding regulatory proteins.
Inspection of the structure of the C-terminal domain of ribosomal protein L7/L12 (1) reveals a helix-turn-helix motif similar to the one found in many DNA-binding regulatory proteins (2-5). The 19 alpha-carbon atoms of the L7/L12 alpha-helices superimpose on the DNA binding helices of CAP and cro with root-mean-square distances between corresponding alpha carbons of 1.45 and 1.55 A, respectively. These helices in L7/L12 are within a patch of highly conserved residues on the surface of L7/L12 whose role is as yet uncertain. We raise the possibility that they may constitute a binding site for nucleic acids, most probably RNA. Consistent with this hypothesis are calculations of the electrostatic charge potential surrounding the protein, which show a region of positive potential centered on the first of these helices.
Rice
P A
PA
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511.
Steitz
T A
TA
D001426:Bacterial Proteins / Q000648:ultrastructure*; D001665:Binding Sites; D004268:DNA-Binding Proteins / Q000648:ultrastructure*; D004926:Escherichia coli / Q000378:metabolism; D005809:Genes, Regulator; D008958:Models, Molecular; D011487:Protein Conformation; D012269:Ribosomal Proteins / Q000378:metabolism / Q000648:ultrastructure*
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D012269:Ribosomal Proteins; C016700:ribosomal protein L7-L12