Initiation of Translation in halophilic Archaea.

翻译是遗传信息表达的一个重要步骤。目前已知的翻译起始机制有四种，即细菌和古细菌使用的基于Shine-Dalgarno基序的机制，真核生物的扫描机制和ires依赖机制，以及在无前导转录本处起始。我们发现大多数盐古菌转录本是无先导的，只有极少数先导转录本包含一个SD序列。无sd引线转录物的诱导不同于所有已知的途径，因此至少在盐古菌中存在一种新的机制。盐古菌翻译起始的分子表征是目前研究的重点，包括起始元件的诱变、三种起始机制的差异使用表征以及起始因子的条件耗竭。翻译的调节通常发生在起始阶段，这是限速的。盐古菌的翻译调控需要5 ' -和3 ' - utr。本文将分析盐古菌的翻译调控机制，包括调控的全局分析、RNA元件的表征和调控因子的鉴定。

Translation is a very important step in the expression of genetic information. Four mechanisms for translation initiation are known, i.e. the Shine-Dalgarno motif-based mechanism used by bacteria and archaea, the scanning mechanism and the IRES-depending mechanism of eukaryotes, and initiation at leaderless transcripts. We dis-covered that the majority of haloarchaeal transcripts are leaderless and that only very few leadered transcripts contain a SD sequence. Initation on SD-less leadered transcript is distinct from all previously known path-ways, therefore a novel mechanism exists at least in haloarchaea. Molecular characterization of translation initiation in haloarchaea is a major focus of the proposed research, including mutagenesis of initiation elements, characterization of differential usage of the three initiation mechanisms, and conditional depletion of initiation factors. Regulation of translation typically occurs during initiation, which is rate-limiting. Translational regulation in haloarchaea requires both 5’- and 3’-UTRs. The mechanism of translational regulation in haloarchaea will be analyzed, including global analysis of regulation, characterization of RNA elements, and identification of regulatory factors.