PROBING THE ASSEMBLY OF THE 3' MAJOR DOMAIN OF 16S-RIBOSOMAL RNA - QUATERNARY INTERACTIONS INVOLVING RIBOSOMAL PROTEIN-S7, PROTEIN-S9 AND PROTEIN-S19
PROBING THE ASSEMBLY OF THE 3' MAJOR DOMAIN OF 16S-RIBOSOMAL RNA - QUATERNARY INTERACTIONS INVOLVING RIBOSOMAL PROTEIN-S7, PROTEIN-S9 AND PROTEIN-S19
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DOI：
10.1016/0022-2836(88)90243-4
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发表时间：
1988-03-20
影响因子：
5.6
通讯作者：
NOLLER, HF
中科院分区：
文献类型：
--
作者：
POWERS, T;CHANGCHIEN, LM;NOLLER, HF
研究了核糖体蛋白S7、S9和S19的组装对16 S核糖体RNA中核苷酸可及性和构象的影响。将16 S rRNA与S7、S7+S9、S7+S19或S7+S19形成的复合物置于化学探针和酶探针的组合下，通过引物延伸确定16 S rRNA中的攻击位点。研究结果表明：（1）蛋白S7影响3“主结构域下半部分的广泛区域的反应性。 蛋白质S9或S19与S7的包含通常对RNA的S7特异性保护几乎没有额外影响。被蛋白S7保护的核苷酸簇位于935-945区域、950/1230茎、1250/1285内环和1350/1370茎。(2)在存在S7的情况下添加蛋白S9主要在两个结构远端区域引起几种额外的效应。我们观察到1278 - 1283位和1125/1145内环中的几个位置的强S9依赖性保护。这些发现表明，蛋白S9与16 S rRNA的相互作用导致了1125/1145和1280区域彼此邻近的结构。(3)大多数强烈的S19依赖效应集中在950-1050和1210-1230区域，这些区域通过16 S rRNA二级结构中的碱基配对连接。高度保守的960-975茎环，这已经牵连在tRNA结合，似乎是不稳定的存在下S19。(4)蛋白S7在几个位点引起增强的反应性，这些位点在加入S9或S19后受到保护。这表明S7诱导的16 S rRNA构象变化在3“主要结构域组装的协同性中起作用。
We have studied the effect of assembly of ribosomal proteins S7, S9 and S19 on the accessibility and conformation of nucleotides in 16 S ribosomal RNA. Complexes formed between 16 S rRNA and S7, S7+S9, S7+S19 or S7+S19 were subjected to a combination of chemical and enzymatic probes, whose sites of attack in 16 S rRNA were identified by primer extension. The results of this study show that: (1) Protein S7 affects the reactivity of an extensive region in the lower half of the 3'' major domain. Inclusion of proteins S9 or S19 with S7 has generally little additional effect on S7-specific protection of the RNA. Clusters of nucleotides that are protected by protein S7 are localized in the 935-945 region, the 950/1230 stem, the 1250/1285 internal loop, and the 1350/1370 stem. (2) Addition of protein S9 in the presence of S7 causes several additional effects principally in two structurally distal regions. We observe strong S9-dependent protection of positions 1278 to 1283, and of several positions in the 1125/1145 internal loop. These findings suggest that interaction of protein S9 with 16 S rRNA results in a structure in which the 1125/1145 and 1280 regions are proximal to each other. (3) Most of the strong S19-dependent effects are clustered in the 950-1050 and 1210-1230 regions, which are joined by base-pairing in the 16 S rRNA secondary structure. The highly conserved 960-975 stem-loop, which has been implicated in tRNA binding, appears to be destabilized in the presence of S19. (4) Protein S7 causes enhanced reactivity at several sites that become protected upon addition of S9 or S19. This suggests that S7-induced conformational changes in 16 S rRNA play a role in the co-operativity of assembly of the 3'' major domain.