Fukuhara T, Moriyama H, Nitta T
Laboratory of Molecular Cell Biology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Japan.
J Biol Chem. 1995 Jul 28;270(30):18147-9. doi: 10.1074/jbc.270.30.18147.
A linear, plasmid-like, double-stranded RNA (dsRNA) was isolated from rice, and its entire sequence of 13,952 nucleotides (nt) was determined. The dsRNA encodes a single, unusually long, open reading frame (13,716 nt, 4,572 amino acid residues), which includes an RNA helicase-like domain and an RNA-dependent RNA polymerase-like domain. A series of Northern hybridization and primer extension experiments revealed that the coding (sense) strand of the dsRNA contains a discontinuity (nick) at a position 1,211 nt (or 1,256 nt) from the 5' end. This discontinuity divides not only the coding strand of dsRNA molecule into a 1,211-nt fragment and a 12,741-nt fragment (or a 1,256-nt fragment and a 12,696-nt fragment) but also divides the long open reading frame into a 5' part of 1,045 nt (348 amino acid residues) and a 3' part of 12,671 nt (4,224 amino acid residues) or a 5' part of 1,090 nt (363 amino acid residues) and a 3' part of 12,626 nt (4,209 amino acid residues). It seems likely that almost all dsRNA molecules in rice plants contain such a discontinuity. This rice dsRNA appears to be a novel and unique RNA replicon.
从水稻中分离出一种线性的、类似质粒的双链RNA（dsRNA），并测定了其13952个核苷酸（nt）的完整序列。该dsRNA编码一个单一的、异常长的开放阅读框（13716 nt，4572个氨基酸残基），其中包括一个RNA解旋酶样结构域和一个RNA依赖性RNA聚合酶样结构域。一系列Northern杂交和引物延伸实验表明，dsRNA的编码（正义）链在距5'端1211 nt（或1256 nt）处存在一个间断（切口）。这种间断不仅将dsRNA分子的编码链分为一个1211 nt的片段和一个12741 nt的片段（或一个1256 nt的片段和一个12696 nt的片段），还将长开放阅读框分为一个1045 nt（348个氨基酸残基）的5'部分和一个12671 nt（4224个氨基酸残基）的3'部分，或一个1090 nt（363个氨基酸残基）的5'部分和一个12626 nt（4209个氨基酸残基）的3'部分。水稻植株中几乎所有的dsRNA分子似乎都含有这样的间断。这种水稻dsRNA似乎是一种新颖独特的RNA复制子。
