適用された力は,転写終結のメカニズム的およびエネルギー的な詳細を明らかにします
Matthew H Larson1, William J Greenleaf, Robert Landick
1Biophysics Program, Stanford University, Stanford, CA 94305, USA.
Cell
|March 25, 2008
まとめ
細菌の転写終結は,RNAヘアピンとU豊富な配列に依存しています. 異なるターミネーターは,ハイパートランスロケーションやハイブリッドシーリングのような異なるメカニズムを使用して,延長複合体を不安定化し,遺伝子調節を確保します.
科学分野:
- 分子生物学は分子生物学である.
- バイオフィジックス 生物物理学
- 遺伝学 遺伝学とは
背景:
- バクテリアの転写終結は,遺伝子調節に極めて重要です.
- それは特定のRNA配列を伴う: GC豊富なヘアピンに続いてU豊富な経路.
- 延長複合体 (EC) は,終結が起こるためには不安定化されなければならない.
研究 の 目的:
- 細菌のRNAポリメラーゼ (RNAP) ターミネーターがECを不安定化するメカニズムを調査する.
- 終結におけるRNAヘアピンとU豊富な領域の役割を区別するために.
- 端末関数の定量モデルを開発する.
主な方法:
- 3つの代表的なターミネーター (his,t500,tR2) を研究するために単一分子技術が採用されました.
- バイアスの転位と力に依存した運動性を評価するために,機械的な負荷が適用されました.
- RNA:DNAハイブリッドのダイナミクスを研究するために,孤立したU経路に緊張が適用されました.
主要な成果:
- 終端効率 (TE) は"his"と"tR2"の終端器の負荷の影響を受けませんでした.
- "t500"のターミネーターは,力に依存した動力学とTEを示し,前向きの転位メカニズムを示唆した.
- U経路切断とヘアピンベースペアリングのダイナミクスは,重要な不安定化要因として特定されました.
- 異なるターミネーターは,ハイパートランスロケーションとハイブリッドシーリングを含む異なるメカニズムを使用します.
結論:
- バクテリアの転写終了には,ターミネーター配列の組成に依存する多様なメカニズムが含まれています.
- RNA:DNAハイブリッド・シーリングとヘアピン・スタビリティは,ECの不安定化に極めて重要です.
- 定量的モデルは,ターミネーターとミュータントの多様性の行動を予測し,遺伝子調節に関する理解を深めることができます.
関連する概念動画
Transcription Attenuation in Prokaryotes
Transcriptional attenuation occurs when RNA transcription is prematurely terminated due to the formation of a terminator mRNA hairpin structure. Bacteria use these hairpins to regulate the transcription process and control the synthesis of several amino acids including histidine, lysine, threonine, and phenylalanine. Transcription attenuation takes place in the non-coding regions of mRNA.
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
Bacterial Transcription
RNA polymerase (RNAP) carries out DNA-dependent RNA synthesis in both bacteria and eukaryotes. Bacteria do not have a membrane-bound nucleus. So, transcription and translation occur simultaneously, on the same DNA template.
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
Transcription 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)...
Transcription 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...
Transcription 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...
Transcription Initiation
Initiation is the first step of transcription in eukaryotes. Prokaryotic RNA Polymerase (RNAP) can bind to the template DNA and start transcribing. On the other hand, transcription in eukaryotes requires additional proteins, called transcription factors, to first bind to the promoter region in the DNA template. This binding helps recruit the specific RNAP that can assemble on the DNA and start transcription.
The promoters and enhancers and their accessory proteins allow tight regulation of...
The promoters and enhancers and their accessory proteins allow tight regulation of...


