Transcription elongation through DNA arrest sites - A multistep process involving both RNA polymerase II subunit RPB9 and TFIIS
Transcription elongation through DNA arrest sites - A multistep process involving both RNA polymerase II subunit RPB9 and TFIIS
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DOI：
10.1074/jbc.272.23.14747
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发表时间：
1997-06-06
影响因子：
4.8
通讯作者：
Edwards, AM
中科院分区：
文献类型：
--
作者：
Awrey, DE;Weilbaecher, RG;Edwards, AM
酵母RNA聚合酶II（pol II）亚基RPB 9在转录延长中的作用通过检查缺少RPB 9的pol II（pol II Delta 9）的生化性质来研究。对于pol II和pol II Delta 9，链延长的最大速率几乎相同。相比之下，pol II Delta 9通过向延伸复合物发出暂停或停滞信号的DNA序列更有效地延伸。将纯化的重组RPB 9添加到pol II Delta 9中使突变聚合酶的延伸性质恢复到野生型酶的延伸性质。被捕的pol II Delta 9复合物对促进pol II最大通读的TFIIS水平是难治的。然而，用TFIIS刺激的pol II和pol II Delta 9复合物都经历转录物切割，证实转录物切割和通读活性可以解偶联。我们的观察表明，TFIIS和RPB 9都需要刺激RNA聚合酶II从被捕状态释放。
The role of yeast RNA polymerase II (pol II) subunit RPB9 in transcript elongation was investigated by examining the biochemical properties of pol II lacking RPB9 (pol II Delta 9). The maximal rate of chain elongation was nearly identical for pol II and pol II Delta 9. By contrast, pol II Delta 9 elongated more efficiently through DNA sequences that signal the elongation complex to pause or arrest. The addition of purified recombinant RPB9 to pol II Delta 9 restored the elongation properties of the mutant polymerase to those of the wild-type enzyme. Arrested pol II Delta 9 complexes were refractory to levels of TFIIS that promoted maximal read-through with pol II. However, both pol II and pol II Delta 9 complexes stimulated with TFIIS undergo transcript cleavage, confirming that transcript cleavage and read-through activities can be uncoupled. Our observations suggest that both TFIIS and RPB9 are required to stimulate the release of RNA polymerase II from the arrested state.