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Author:
Date:
2012-08-20
[Abstract] This protocol describes yeast ribosome fractionation in the gradient of sucrose. During the cyclic process of translation, a small (40S) and large (60S) ribosomal subunit associate with mRNA to form an 80S complex (monosome). This ribosome moves along the mRNA during translational elongation, and then dissociates into the 40S and 60S subunits on termination. During elongation by one ribosome, further ribosomes can initiate translation on the same mRNA to form polysomes. The mass of each polysomal complex is determined primarily by the number of ribosomes it contains. Hence, the population of polysomes within the cell can be size-fractionated by sucrose density gradient centrifugation on the basis of the loading of ribosomes on the mRNA. Several compounds help to maintain or to disrupt the ...
[摘要] 该协议描述了在蔗糖梯度中的酵母核糖体分级。 在翻译的循环过程中，小（40S）和大（60S）核糖体亚基与mRNA结合以形成80S复合物（单体）。 这种核糖体在翻译延长过程中沿着mRNA移动，然后在终止时解离成40S和60S亚基。 在由一个核糖体延伸期间，另外的核糖体可以在相同的mRNA上启动翻译以形成多核糖体。 每个多核糖体复合物的质量主要由其包含的核糖体的数量决定。 因此，通过蔗糖密度梯度离心，基于mRNA上核糖体的加载，可以对细胞内多核糖体群进行大小分级。 几种化合物有助于维持或破坏多核糖体（图1）。
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