細菌における転写停止の構造的基礎
Albert Weixlbaumer1, Katherine Leon, Robert Landick
1The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
Cell
|February 5, 2013
まとめ
RNAポリメラーゼ (RNAP) の停止は,遺伝子調節と終結に不可欠です. 私たちは,停滞したRNAP延長複合体の結晶構造を決定し,核酸添加を阻害し,終了を助ける形状を明らかにしました.
科学分野:
- 分子生物学は分子生物学である.
- バイオケミストリー バイオケミストリー
- 構造生物学 構造生物学とは
背景:
- マルチサブユニットRNAポリメラーゼ (RNAP) による転写停止は,生命のあらゆる領域における遺伝子発現と転写終了を調節する根本的なメカニズムである.
- この一時停止は,核酸添加を阻害する一般的な元素の一時停止状態から発生すると考えられています.
- この休止状態の構造的基礎を理解することは,遺伝子調節と終結プロセスを解明する鍵です.
研究 の 目的:
- RNAポリメラーゼにおける元素の休止状態の構造的基礎を解明する.
- この一時停止状態が,どのように触媒的活動を抑制し,転写終了を容易にするかを理解するために.
主な方法:
- X線結晶グラフィーです.
- サームスRNAPの3つの結晶構造の決定 基本的一時延伸複合体 (ePECs).
主要な成果:
- 結晶構造は,ePECで一貫したリラックスした,オープンクランプのRNAPコンフォームを明らかにしました.
- この形状は,転位時にDNAの接触を再確立できないことから生じる.
- 歪んだブリッジヘリックスがRNAP活性部位をステリカルにブロックし,触媒活性を抑制することが観察されました.
結論:
- 特定されたRNAP構成は,一時停止中に抑制された核酸添加の構造的な説明を提供します.
- この基本的休止状態は,RNAのヘアピン安定化と転写終了の重要な中間体として機能します.
- この発見は,一時停止,RNA構造,終結メカニズムとの相互作用を理解するための枠組みを提供します.
関連する概念動画
02:35Transcription Elongation Factors
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01:53Bacterial Transcription
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Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
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02:35Transcription Elongation Factors
Transcription elongation is a dynamic process that alters depending upon the sequence heterogeneity of the DNA being transcribed. Hence, it is not surprising that the elongation complex's composition also varies along the way while transcribing a gene.
The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA into a...
The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA into a...
01:28Transcription in Prokaryotes
Transcription is a highly regulated process that converts genetic information into RNA molecules. The transcription cycle is divided into three key stages: initiation, elongation, and termination, each driven by specific molecular mechanisms.Initiation of TranscriptionIn bacteria, transcription begins when the RNA polymerase core enzyme associates with a sigma factor to form a holoenzyme. For example, the E. coli sigma factor called σ70 forms a holoenzyme, which recognizes the -10 (Pribnow box)...
01:29Coordination of Gene Expression Processes in Bacteria
The DNA replication, transcription, and translation processes are intricately coupled in bacteria, allowing efficient gene expression and rapid protein synthesis. While this physical and functional coordination is advantageous, it introduces challenges that bacteria overcome through specific regulatory mechanisms.Coupling of Replication, Transcription, and TranslationThe coupling of replication, transcription, and translation is a hallmark of bacterial gene expression. As the replisome unwinds...