RNA沉默
抄写(语言学)
生物
核糖核酸
RNA聚合酶
RNA依赖性RNA聚合酶
RNA聚合酶Ⅱ
衣壳
细胞生物学
分子生物学
遗传学
病毒
基因
基因表达
RNA干扰
发起人
哲学
语言学
作者
Yanxiang Cui,Y. Zhang,Kang Zhou,Jingchen Sun,Z. Hong Zhou
标识
DOI:10.1038/s41594-019-0320-0
摘要
Endogenous RNA transcription characterizes double-stranded RNA (dsRNA) viruses in the Reoviridae, a family that is exemplified by its simple, single-shelled member cytoplasmic polyhedrosis virus (CPV). Because of the lack of in situ structures of the intermediate stages of RNA-dependent RNA polymerase (RdRp) during transcription, it is poorly understood how RdRp detects environmental cues and internal transcriptional states to initiate and coordinate repeated cycles of transcript production inside the capsid. Here, we captured five high-resolution (2.8-3.5 Å) RdRp-RNA in situ structures-representing quiescent, initiation, early elongation, elongation and abortive states-under seven experimental conditions of CPV. We observed the 'Y'-form initial RNA fork in the initiation state and the complete transcription bubble in the elongation state. These structures reveal that de novo RNA transcription involves three major conformational changes during state transitions. Our results support an ouroboros model for endogenous conservative transcription in dsRNA viruses.
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