Rice P A, Steitz T A
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511.
Nucleic Acids Res. 1989 May 25;17(10):3757-62. doi: 10.1093/nar/17.10.3757.
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.
对核糖体蛋白L7/L12 C末端结构域的检查（1）发现了一种螺旋-转角-螺旋基序，类似于在许多DNA结合调节蛋白中发现的基序（2-5）。L7/L12 α螺旋的19个α碳原子分别与CAP和cro的DNA结合螺旋重叠，相应α碳原子之间的均方根距离分别为1.45 Å和1.55 Å。L7/L12中的这些螺旋位于L7/L12表面高度保守的残基区域内，其作用尚不确定。我们提出它们可能构成核酸结合位点的可能性，很可能是RNA。围绕该蛋白的静电荷电势计算结果与这一假设一致，计算结果显示以这些螺旋中的第一个为中心的正电势区域。
