Dohme F, Nierhaus K H
Proc Natl Acad Sci U S A. 1976 Jul;73(7):2221-5. doi: 10.1073/pnas.73.7.2221.
Total reconstitution experiments performed under various conditions revealed that 5S RNA plays an important role during the last assembly step in vitro leading to an active 50S particle. For the preceding steps this RNA species is dispensable. However, 50S RNA can be integrated efficiently during any of the assembly steps in vitro. The 47S particle, reconstituted in two steps and lacking 5S RNA, shows low but significant activity in many functional tests. High activity could be obtained by incubating this particle with 5S RNA alone, demonstrating the importance of the 5S RNA in generating an active ribosomal conformation. In particular, the activity of the peptidyltransferase (peptidyl-tRNA:aminoacyl-tRNA N-peptidyltransferase; EC 2.3.2.12) center is drastically influenced by 5S RNA. No significant factor-dependent tRNA binding to the A-site was observed with the 47S particle, in contrast to the corresponding P-site binding. The elongation factor G dependent GTPase activity was not affected by the lack of 5S RNA.
在各种条件下进行的完全重组实验表明，5S RNA在体外导致活性50S颗粒形成的最后组装步骤中发挥重要作用。对于之前的步骤，这种RNA种类是可有可无的。然而，50S RNA可以在体外的任何组装步骤中高效整合。分两步重组且缺乏5S RNA的47S颗粒在许多功能测试中显示出低但显著的活性。通过单独将该颗粒与5S RNA孵育可获得高活性，这证明了5S RNA在产生活性核糖体构象中的重要性。特别是，肽基转移酶（肽基-tRNA：氨酰-tRNA N-肽基转移酶；EC 2.3.2.12）中心的活性受到5S RNA的显著影响。与相应的P位点结合相反，47S颗粒未观察到明显的因子依赖性tRNA与A位点的结合。缺乏5S RNA并不影响延伸因子G依赖性GTP酶活性。
