ASSEMBLY OF BACTERIAL RIBOSOMES
ASSEMBLY OF BACTERIAL RIBOSOMES
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DOI：
10.1002/jss.400020210
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发表时间：
1974-01-01
期刊：
影响因子：
--
通讯作者：
NOMURA M
中科院分区：
文献类型：
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作者：
NOMURA M
重组和功能分析的一个例子是鉴定参与自然mRNA翻译起始的核糖体成分(1)。大肠杆菌的30个亚单位可以在体外高效地启动RNA噬菌体R17的外壳顺反子翻译，而嗜热脂肪芽孢杆菌的30个亚单位则不能。为了鉴定造成这种差异的核糖体成分，使用大肠杆菌16s RNA和纯化的大肠杆菌蛋白与嗜脂嗜热杆菌成分的混合物进行重组，单独或联合替代相应的大肠杆菌成分。结果发现，在单独检测的17种B. stearothermophilus蛋白中，只有替代B. stearothermophilus S12导致R17 RNA的翻译量较poly u显著降低（50%），而其他蛋白均未表现出这种效果。除了S12外，B.硬脂嗜热菌16s RNA的取代也导致这种能力降低了40 - 50%，B.硬脂嗜热菌S12和16s RNA的取代导致这种能力降低（85%）到天然B.硬脂嗜热菌30s亚基的水平。这些实验和其他实验表明，S12不仅在一般起始功能中至关重要(2)，而且与16s RNA一起，在决定R17 RNA外壳顺反子起始效率方面也起着重要作用(1)。16s RNA与mRNA起始位点之间可能存在直接相互作用。
One example of reconstitution and functional analysis is the identification of the ribosomal components involved in the initiation of natural mRNA translation (1). While Escherichia coli 30s subunits can initiate translation of the coat cistron of RNA phage R17 with high efficiency in vitro, 30s subunits from Bacillus stearothermophilus cannot. To identify the ribosomal components responsible for this difference, reconstitution was performed using E. coli 16s RNA and a mixture of purified E. coli proteins with B. Stearothermophilus components, singly or in combination, substituted for the corresponding E. coli components. It was found that among 17 B. stearothermophilus proteins examined individually, only substitution of B. stearothermophilus S12 resulted in a significant decrease (50%) in the translation of R17 RNA relative to that of poly U. None of the other proteins showed such an effect. In addition to S12, substitution of B. stearothermophilus 16s RNA also caused a 40 to 50% reduction in this ability, and substituion of both B. stearothermophilus S12 and 16s RNA caused a reduction (85%) to the level exhibited by native B. stearothermophilus 30s subunits. These and other experiments indicate that S12 is not only crucial in the general initiation function (2), but also plays an important role, in conjunction with 16s RNA, in determining the efficiency of initiation at the coat cistron of R17 RNA (1). A possible direct interaction between 16s RNA and mRNA initiation sites is suggested.