A conserved inverted repeat from rice plastome functions as an intrinsic transcription terminator  

作　　者：LIN Chi-Hui LIANG Yu-din CHEN Liang-Jwu 

机构地区：[1]Institute of Molecular Biology, National Chung-Hsing University,Taichung 402, Taiwan, China [2]Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan, China

出　　处：《Chinese Science Bulletin》2005年第15期1669-1672,共4页

摘　　要：Results from a previous rice transcription mapping and the GeSTer algorithm analysis used in this in-vestigation for rice plastid genome suggest that an inverted repeat, IRs18, in 3′ region of the plastid rps18 gene may serve as a transcription terminator. The in vitro transcription assay showed that the transcript ending at the IRs18 was not proc-essed by ribonucleases but terminated intrinsically in an rNTP substrate-dependent manner as demonstrated for the first time in plant gene regulation. For the poly-T tract (TTCTTTTTT) 3′-proximal to the IRs18, the C base conver-sion to T resulting in a perfect 9 Ts can dramatically increase termination efficiency, which is a common feature of bacte-rial intrinsic termination. This study is the first case to indi-cate that a conserved inverted repeat with a poly-T tract from higher plant chloroplast contributes to transcription termination of the translation-associated rps18 gene in a manner with the intrinsic termination, probably resulting from a heritage of endosymbiosis.Results from a previous rice transcription mapping and the GeSTer algorithm analysis used in this investigation for rice plastid genome suggest that an inverted repeat, IRs18, in 3＇ region of the plastid rps18 gene may serve as a transcription terminator. The in vitro transcription assay showed that the transcript ending at the IRs18 was not processed by ribonucleases but terminated intrinsically in an rNTP substrate-dependent manner as demonstrated for the first time in plant gene regulation. For the poly-T tract （TTCTTTTTT） 3＇-proximal to the IRs18, the C base conversion to T resulting in a perfect 9 Ts can dramatically increase termination efficiency, which is a common feature of bacte- rial intrinsic termination. This study is the first case to indi- cate that a conserved inverted repeat with a poly-T tract from higher plant chloroplast contributes to transcription termination of the translation-associated rps18 gene in a manner with the intrinsic termination, probably resulting from a heritage of endosymbiosis.

关 键 词：水稻 叶绿体 转录基因 反向重复 质体 基因组 

分 类 号：Q949.714.2[生物学—植物学]