Blokhin Dmitriy S, Bikmullin Aydar G, Nurullina Liliya I, Garaeva Natalia S, Validov Shamil Z, Klochkov Vladimir V, Aganov Albert V, Khusainov Iskander Sh, Yusupov Marat M, Usachev Konstantin S
Laboratory of Structural Biology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 18 Kremlevskaya, Kazan, Russian Federation, 420008.
NMR Laboratory, Medical Physics Department, Institute of Physics, Kazan Federal University, 18 Kremlevskaya, Kazan, Russian Federation, 420008.
Biomol NMR Assign. 2019 Apr;13(1):27-30. doi: 10.1007/s12104-018-9845-0. Epub 2018 Sep 17.
Ribosome binding factor A (RbfA) is a 14.9 kDa adaptive protein of cold shock, which is important for bacterial growth at low temperatures. RbfA can bind to the free 30S ribosomal subunit and interacts with the 5'-terminal helix (helix I) of 16S rRNA. RbfA is important for the efficient processing of 16S rRNA and for the maturation (assembly) of 30S ribosomal subunits. Here we report backbone and side chains H, C and N chemical shift assignments of RbfA from Staphylococcus aureus. Analysis of the backbone chemical shifts by TALOS+ suggests that RbfA contains four α-helixes and three β-strands with α1-β1-β2-α2-α3-β3-α4 topology. Secondary structure of RbfA have KH-domain fold topology with βααβ subunit which is characterized by a helix-kink-helix motif in which the GxxG sequence is replaced by a conserved AxG sequence, where an Ala residue at position 70 forming an interhelical kink. The solution of the structure of this protein factor and its complex with the ribosome by NMR spectroscopy, X-ray diffraction analysis and cryo-electron microscopy will allow further development of highly selective substances for slowing or completely stopping the translation of the pathogenic bacterium S. aureus, which will interfere with the synthesis and isolation of its pathogenicity factors.
核糖体结合因子A（RbfA）是一种14.9 kDa的冷休克适应性蛋白，对细菌在低温下的生长很重要。RbfA可以结合游离的30S核糖体亚基，并与16S rRNA的5'-末端螺旋（螺旋I）相互作用。RbfA对16S rRNA的有效加工以及30S核糖体亚基的成熟（组装）很重要。在此，我们报告了来自金黄色葡萄球菌的RbfA的主链以及侧链H、C和N化学位移归属。通过TALOS +对主链化学位移的分析表明，RbfA包含四个α-螺旋和三条β-链，其拓扑结构为α1-β1-β2-α2-α3-β3-α4。RbfA的二级结构具有KH结构域折叠拓扑，带有βααβ亚基，其特征在于螺旋-扭结-螺旋基序，其中GxxG序列被保守的AxG序列取代，其中70位的丙氨酸残基形成螺旋间扭结。通过核磁共振光谱、X射线衍射分析和冷冻电子显微镜解析该蛋白质因子及其与核糖体复合物的结构，将有助于进一步开发高选择性物质，以减缓或完全阻止致病性金黄色葡萄球菌的翻译，这将干扰其致病因子的合成和分离。
