MerR重金属受容体は,トポロジ的に新しい転写複合体のポジティブな活性化を媒介する
T V O'Halloran1, B Frantz, M K Shin
1Department of Chemistry, Northwestern University, Evanston, Illinois 60208.
Cell
|January 13, 1989
まとめ
重金属のストレスは,MerRタンパク質を通じて細菌の遺伝子発現を誘発し,それは水銀イオン耐性オペレオンを直接活性化します. このタンパク質-DNAの相互作用は,転写制御のためのRNAポリメラーゼとのユニークな空間的配置を含んでいます.
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
- 遺伝学 遺伝学とは
背景:
- 細胞外信号に対する細胞の反応には,複雑な遺伝子発現経路が含まれています.
- ヘビーメタルのストレス反応のメカニズムは,ほとんど未知のままです.
- バクテリアの重金属耐性は,生存に不可欠です.
研究 の 目的:
- 細菌の重金属ストレス反応のメカニズムを解明する.
- 転写活性化におけるMerRタンパク質の役割を特定する.
- 重金属の信号が遺伝子発現の変化に変換される方法を理解する.
主な方法:
- MerRタンパク質,水銀イオン,RNAポリメラーゼの相互作用を研究した.
- バクテリアの水銀イオン抵抗オペロンプロモーターにMerR-水銀イオン複合体の結合を分析した.
- 結合タンパク質とDNAの空間的関係を決定するために構造生物学技術を活用しました.
主要な成果:
- MerRタンパク質は,水銀イオン耐性オペラントの転写を直接活性化します.
- 水銀イオン-MerR複合体とRNAポリメラーゼホロ酵素は,プロモーターに相乗的に結合する.
- -35と -10の領域の間のRNAポリメラーゼ結合とMerRが重複する前例のない空間的配置が観察されました.
- タンパク質とタンパク質の相互作用とDNAの構造的変化を含む転写活性化のモデルが支持されました.
結論:
- MerRは重金属受容体と転写活性化剤として直接作用する.
- 協同作用の結合とユニークな空間的配置は,重金属のストレス下での遺伝子発現を活性化するための鍵です.
- 転写活性化には,効果因子誘発のタンパク質相互作用とDNA構造の変化の両方が含まれます.
関連する概念動画
RNA Polymerase II Accessory Proteins
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...
Co-activators and Co-repressors
Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into...
Eukaryotic Transcription Activators
Transcription activators are proteins that promote the transcription of genes from DNA to RNA. In most cases, these proteins contain two separate domains ‒ a domain that binds to DNA and a domain for activating transcription; however, in some cases, a single domain is responsible for both binding and activation of transcription, as seen in the glucocorticoid receptor and MyoD.
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These domains are...
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These domains are...
Master Transcription Regulators
Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...
Co-activators and Co-repressors
Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into...
Master Transcription Regulators
Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...


