B. subtilisの調節タンパク質TRAPをTRAP阻害タンパク質ATによって抑制する
1Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA.
Science (New York, N.Y.)
|September 15, 2001
まとめ
新しく発見された抗TRAP (AT) タンパク質は,TRAPタンパク質を阻害し,トリプトファン産生を促進することによって,細胞トリプトファンが低いことをシグナルします. このメカニズムは,E. coliのメカニズムと異なる.
科学分野:
- 分子生物学は分子生物学である.
- 微生物生理学とは
- 遺伝子規制 遺伝子規制
背景:
- トリプトファンのバイオシンセシスは,バクテリアで厳格に規制されています.
- trpオペロン減衰タンパク質 (TRAP) は,バチルス・サブティリスのトリプトファン生成を制御する.
- 抗TRAP (AT) タンパク質の機能は以前は知られていなかった.
研究 の 目的:
- 抗TRAP (AT) タンパク質の機能を明らかにする.
- ATがトリプトファン生物合成をどのように調節するかを理解するために.
- バシルス・サブティリスとエシェリキア・コライにおけるトリプトファン生物合成の調節を比較する.
主な方法:
- ATとTRAPの相互作用を調査しました.
- TRAPのRNA結合活動に対するATの効果を分析した.
- 未充電のtRNAによってAT発現の誘導を研究した.
- ATのホモロジーを他のタンパク質と比較した.
主要な成果:
- ATは,トリプトファン生物合成を調節するために,未充電のtRNAレベルをシグナルします.
- ATはRNAへのTRAP結合を阻害し,転写抑制を緩和する.
- AT発現は,未充電のtRNAによって誘発される.
- ATは,トリプトファンで活性化されたTRAPの形に結合する.
- ATは,DnaJの亜鉛結合ドメインとホモロジーを共有しています.
結論:
- ATは,tRNAが充電されていないときにトリプトファンのバイオシンセシスを増加させる代謝信号として作用します.
- バシルス・サブティリスのATに関与する規制メカニズムは,Escherichia coli.のATとは異なる.
- ATは,バクテリアのトリプトファン代謝経路における新しい成分を表しています.
さらに関連する動画
10:26TRAP-rc, Translating Ribosome Affinity Purification from Rare Cell Populations of Drosophila Embryos
Published on: September 10, 2015
09:41Translating Ribosome Affinity Purification (TRAP) to Investigate Arabidopsis thaliana Root Development at a Cell Type-Specific Scale
Published on: May 14, 2020
関連する概念動画
02:42Transcription 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...
01:26Bacterial Protein Maturation
Bacterial protein maturation is a tightly regulated process that ensures newly synthesized polypeptides achieve correct functional conformations. This maturation involves a series of modifications, folding events, and quality control steps, often assisted by specialized chaperone proteins.N-Terminal ModificationsThe maturation of bacterial polypeptides begins cotranslationally as the polypeptide exits the ribosome. The first amino acid, N-formylmethionine (fMet), is typically modified at the...
01:21Repressible Operon: trp Operon
The trp operon in Escherichia coli exemplifies a repressible operon. It regulates the synthesis of tryptophan through repressor-mediated transcriptional control and attenuation. This dual regulatory mechanism ensures tryptophan biosynthesis occurs only when needed, conserving cellular resources.Structure of the trp OperonThe trp operon consists of five structural genes (trpE, trpD, trpC, trpB, and trpA) that encode enzymes for tryptophan biosynthesis. These genes are transcribed as a single...
01:29Translational Regulation
Translational regulation in prokaryotes ensures efficient protein synthesis by controlling ribosome access to mRNA. This regulation is mediated by secondary RNA structures, including translational riboswitches, RNA thermometers, and small RNAs (sRNAs), which respond to intracellular and environmental signals to modulate gene expression.Translational RiboswitchesRiboswitches in the leader region of mRNAs can regulate translation by altering the accessibility of the Shine-Dalgarno (SD) sequence,...
01:23Stringent Response in E. coli
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
01:25Inhibitors of Bacterial Protein Synthesis
Aminoglycosides constitute a highly potent class of bactericidal antibiotics that exert their antimicrobial effects by targeting the bacterial ribosome, specifically disrupting protein synthesis. These polycationic molecules consist of amino-modified sugars linked via glycosidic bonds to an aminocyclitol core such as 2-deoxystreptamine or streptamine. Their strong positive charges facilitate tight binding to the negatively charged phosphate backbone of ribosomal RNA (rRNA), primarily at the 16S...