Mutational analysis of the core and modulator sequences of the BMV RNA3 subgenomic promoter.
Mutational analysis of the core and modulator sequences of the BMV RNA3 subgenomic promoter.
复制标题
BMV RNA3 亚基因组启动子的核心和调节序列的突变分析。
DOI：
10.1093/nar/16.3.981
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发表时间：
1988
影响因子：
14.9
通讯作者：
Hall,TC
中科院分区：
文献类型：
--
作者：
Marsh,LE;Dreher,TW;Hall,TC
一种（+）链RNA病毒，溴代花叶病毒（BMV）控制亚基因组RNA4合成的亚基因组启动子已经在体外被确定。通过体外转录克隆的RNA3 cDNA得到截断和突变的（−）链RNA模板。从感染的大麦叶片中提取复制酶（RNA依赖的RNA聚合酶），从这些模板中体外合成亚基因组（+）感RNA。RNA4起始位点周围截断和缺失的模板的活性揭示了一个大约62个碱基的启动子，分为四个功能域。核心序列由大约20个碱基组成，直接位于起始核苷酸的上游，包括起始核苷酸。除了核心序列外，与RNA4的5 '非翻译端重叠的结构域显然决定了正确的起始。启动子核心上游的两个结构域由RNA3的内部poly(A) tract组成，它可能作为一个非碱基配对的间隔物，促进复制酶进入启动子，以及一个高水平启动子活性所需的序列，UUAUUAUU。已经检测到与几种植物RNA病毒和aiphavirus的亚基因组RNA起始位点周围序列的同源性。
The subgenomic promoter of a (+)-stranded RNA virus, brome mosaic virus (BMV) controlling synthesis of subgenomic RNA4 has been defined in vitro. Truncated and mutant (−)-strand RNA templates were produced byin vitrotranscription of cloned RNA3 cDNA. Subgenomic (+)-sense RNA was synthesizedin vitrofrom these templates by a replicase (RNA-dependent RNA polymerase) preparation extracted from infected barley leaves. The activities of templates with truncations and deletions surrounding the RNA4 initiation site revealed a promoter of approximately 62 bases grouped into four functional domains. The core sequence consists of about twenty bases immediately upstream of, and including, the initiation nucleotide. In addition to the core sequence, a domain overlapping the 5′ untranslated end of RNA4 apparently determines correct initiation. Two domains immediately upstream of the promoter core consist of the internal poly(A) tract of RNA3, which probably serves as an non base-paired spacer facilitating access of the replicase to the promoter, and a sequence, UUAUUAUU, that is required for high levels of promoter activity. Homologies to sequences surrounding the initiation sites of subgenomic RNAs from several plant RNA viruses, and from aiphaviruses, have been detected.