Gruber Thomas, Köhrer Caroline, Lung Birgit, Shcherbakov Dmitri, Piendl Wolfgang
Institute of Medical Chemistry and Biochemistry, University of Innsbruck, Fritz-Pregl-Str 3, A-6020 Innsbruck, Austria.
FEBS Lett. 2003 Aug 14;549(1-3):123-8. doi: 10.1016/s0014-5793(03)00760-9.
The ribosomal protein S8 plays a pivotal role in the assembly of the 30S ribosomal subunit. Using filter binding assays, S8 proteins from mesophilic, and (hyper)thermophilic species of the archaeal genus Methanococcus and from the bacteria Escherichia coli and Thermus thermophilus were tested for their affinity to their specific 16S rRNA target site. S8 proteins from hyperthermophiles exhibit a 100-fold and S8 from thermophiles exhibit a 10-fold higher affinity than their mesophilic counterparts. Thus, there is a striking correlation of affinity of S8 proteins for their specific RNA binding site and the optimal growth temperatures of the respective organisms. The stability of individual rRNA-protein complexes might modulate the stability of the ribosome, providing a maximum of thermostability and flexibility at the growth temperature of the organism.
核糖体蛋白S8在30S核糖体亚基的组装中起关键作用。利用滤膜结合试验，对嗜温古菌属甲烷球菌、（超）嗜热古菌属甲烷球菌、大肠杆菌和嗜热栖热菌的S8蛋白与其特定16S rRNA靶位点的亲和力进行了测试。来自嗜热菌的S8蛋白的亲和力比嗜温菌的S8蛋白高100倍，来自嗜热菌的S8蛋白的亲和力比嗜温菌的S8蛋白高10倍。因此，S8蛋白与其特定RNA结合位点的亲和力与相应生物体的最佳生长温度之间存在显著相关性。单个rRNA-蛋白复合物的稳定性可能会调节核糖体的稳定性，在生物体的生长温度下提供最大的热稳定性和灵活性。
