Transcription of a silkworm tRNA(cAla) gene is directed by two AT-rich upstream sequence elements.
Transcription of a silkworm tRNA(cAla) gene is directed by two AT-rich upstream sequence elements.
复制标题
家蚕 tRNA(cAla) 基因的转录由两个富含 AT 的上游序列元件指导。
DOI：
10.1093/nar/21.25.5875
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发表时间：
1993
影响因子：
14.9
通讯作者：
Sprague,KU
中科院分区：
文献类型：
--
作者：
Palida,FA;Hale,C;Sprague,KU
多种家蚕III类模板转录起始位点上游35个核苷酸内的区域是体外转录所必需的。为了确定该区域的活性是否归因于特定的序列元件，我们系统地替换了蚕tRNAcAlagene上游区域的4 - 5bp片段。我们发现，替换两个富含at的片段中的任何一个显著损害启动子功能，而替换其他序列几乎没有影响。构建额外的突变体以测试碱基组成或序列对AT块的功能是否重要。我们发现一些序列比其他序列更有效，但各种富含at的序列可以在高水平上指导转录。讨论了这些因素起作用的可能机制。
A region within 35 nucleotides upstream of the transcription initiation site of a variety of silkworm Class III templates is absolutely required for transcriptionin vitro. To determine whether the activity of this region can be attributed to a particular sequence element, we systematically replaced 4 - 5 bp segments of the region upstream of a silkworm tRNAcAlagene. We show that replacement of either of two AT-rich blocks markedly impairs promoter function, whereas replacement of other sequences has little or no effect. Additional mutants were constructed to test whether base composition or sequence is important for function of the AT blocks. We find that some sequences are more effective than others, but that various AT-rich sequences can direct transcription at a high level. Possible mechanisms by which such elements could act are discussed.