Usachev Konstantin S, Ayupov Rustam Kh, Validov Shamil Z, Khusainov Iskander Sh, Yusupov Marat M
NMR laboratory, Medical Physics Department, Institute of Physics, Kazan Federal University, 18 Kremlevskaya, Kazan, Russian Federation, 420008.
Laboratory of Structural Biology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 18 Kremlevskaya, Kazan, Russian Federation, 420008.
Biomol NMR Assign. 2018 Apr;12(1):85-89. doi: 10.1007/s12104-017-9783-2. Epub 2017 Oct 4.
Staphylococcus aureus: hibernation-promoting factor (SaHPF) is a 22.2 kDa stationary-phase protein that binds to the ribosome and turns it to the inactive form favoring survival under stress. Sequence analysis has shown that this protein is combination of two homolog proteins obtained in Escherichia coli-ribosome hibernation promoting factor (HPF) (11,000 Da) and ribosome modulation factor RMF (6500 Da). Binding site of E. coli HPF on the ribosome have been shown by X-ray study of Thermus thermophilus ribosome complex. Hence, recent studies reported that the interface is markedly different between 100S from S. aureus and E. coli. Cryo-electron microscopy structure of 100S S. aureus ribosomes reveal that the SaHPF-NTD binds to the 30S subunit as observed for shorter variants of HPF in other species and the C-terminal domain (CTD) protrudes out of each ribosome in order to mediate dimerization. SaHPF-NTD binds to the small subunit similarly to its homologs EcHPF, EcYfiA, and a plastid-specific YfiA. Furthermore, upon binding to the small subunit, the SaHPF-NTD occludes several antibiotic binding sites at the A site (hygromycin B, tetracycline), P site (edeine) and E site (pactamycin, kasugamycin). In order to elucidate the structure, dynamics and function of SaHPF-NTD from S. aureus, here we report the backbone and side chain resonance assignments for SaHPF-NTD. Analysis of the backbone chemical shifts by TALOS+ suggests that SaHPF-NTD contains two α-helices and four β-strands (β1-α1-β2-β3-β4-α2 topology). Investigating the long-term survival of S. aureus and other bacteria under antibiotic pressure could lead to advances in antibiotherapy.
促冬眠因子（SaHPF）是一种22.2 kDa的稳定期蛋白，它与核糖体结合并使其转变为无活性形式，有利于在应激条件下存活。序列分析表明，该蛋白是在大肠杆菌核糖体促冬眠因子（HPF，11,000 Da）和核糖体调节因子RMF（6500 Da）中获得的两种同源蛋白的组合。嗜热栖热菌核糖体复合物的X射线研究显示了大肠杆菌HPF在核糖体上的结合位点。因此，最近的研究报道，金黄色葡萄球菌和大肠杆菌的100S核糖体之间的界面明显不同。金黄色葡萄球菌100S核糖体的冷冻电子显微镜结构显示，与其他物种中较短的HPF变体一样，SaHPF-NTD与30S亚基结合，并且C末端结构域（CTD）从每个核糖体中伸出以介导二聚化。SaHPF-NTD与其同源物EcHPF、EcYfiA和质体特异性YfiA类似地结合到小亚基上。此外，在结合到小亚基后，SaHPF-NTD封闭了A位点（潮霉素B、四环素）、P位点（依地菌素）和E位点（春日霉素、卡那霉素）的几个抗生素结合位点。为了阐明金黄色葡萄球菌中SaHPF-NTD的结构、动力学和功能，我们在此报告了SaHPF-NTD的主链和侧链共振归属。通过TALOS+对主链化学位移的分析表明，SaHPF-NTD包含两个α螺旋和四条β链（β1-α1-β2-β3-β4-α2拓扑结构）。研究金黄色葡萄球菌和其他细菌在抗生素压力下的长期存活可能会推动抗微生物治疗的进展。
