INTRODUCTION OF HIDDEN BREAKS DURING RIBOSOMAL-RNA MATURATION AND AGING IN TETRAHYMENA-PYRIFORMIS
INTRODUCTION OF HIDDEN BREAKS DURING RIBOSOMAL-RNA MATURATION AND AGING IN TETRAHYMENA-PYRIFORMIS
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DOI：
10.1111/j.1432-1033.1978.tb12413.x
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发表时间：
1978-01-01
期刊：
影响因子：
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通讯作者：
FRANKE, WW
中科院分区：
文献类型：
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作者：
ECKERT, WA;KAFFENBERGER, W;FRANKE, WW
T.用聚丙烯酰胺凝胶电泳法研究了梨形藻细胞质rRNA和核rRNA前体在部分变性和完全变性条件下的变化。细胞质17-S rRNA（Mr [分子比] = 0.66 × 10 - 15）106)在其整个生命周期中由连续的多核苷酸链组成，而26-S rRNA（Mr = 1.27 × 1.25）的大部分在其整个生命周期中由连续的多核苷酸链组成，而26-S rRNA的大部分在其整个生命周期中由连续的多核苷酸链组成。106)在变性时解离。两个大片段（F1，F2）具有稍微不同的MW（Mr0.63 × Mr0.63）。106和0.58 ×106)5.8SrRNA小片段（Mr约50，000）。在某些制备条件下观察到一些额外的不同次要片段（F3-F6），提示人为来源。根据所获得的数据得出结论。新合成的26-S rRNA分子在细胞质中出现约15分钟后才含有中心隐藏断裂（分离F1和F2），但它们在变性过程中释放5.8-S和/或短寿命的7-S片段（Mr约75，000），这可能是5.8-S rRNA的直接前体。26-S rRNA的直接核前体（Mr 1.39 × 1.25）。106)释放类似大小的小片段（7S）。rDNA的最大稳定转录产物（pre-rRNA）不包含任何隐藏的断裂。
The stability of T. pyriformis cytoplasmic rRNA and nuclear rRNA precursors was studied by polyacrylamide gel electrophoresis under partly and completely denaturing conditions. Cytoplasmic 17-S rRNA (Mr [molecular ratio] = 0.66 .times. 106) consists of a continuous polynucleotide chain throughout its lifetime, whereas the bulk of 26-S rRNA (Mr = 1.27 .times. 106) dissociates upon denaturation. Two large fragments (F1, F2) of somewhat different MW (Mr 0.63 .times. 106 and 0.58 .times. 106) and the small 5.8-S rRNA fragment (Mr about 50,000) are regularly observed. Some additional distinct minor fragments (F3-F6) are noted under certain preparative conditions, suggestive of artifactual origin. Conclusions were made from the data obtained. Newly synthesized 26-S rRNA molecules do not contain the central hidden break (separating F1 and F2) until about 15 min after their appearance in the cytoplasm, but they release during denaturation the 5.8-S and/or a short-lived 7-S fragment (Mr about 75,000) which might represent a direct precursor to the 5.8-S rRNA. The immediate nuclear precursor to the 26-S rRNA (Mr 1.39 .times. 106) releases a small fragment of similar size (7 S). The largest stable transcription product of the rDNA (pre-rRNA) does not contain any hidden break.