タンパク質のリン酸化は,E. coliにおけるβ-グルコシド利用オペロンの転写を調節する
O Amster-Choder1, F Houman, A Wright
1Department of Molecular Biology and Microbiology, Tufts University Health Sciences Campus, Boston, Massachusetts 02111.
Cell
|September 8, 1989
まとめ
E. coliのBglFタンパク質は,陽性調節体であるBglGをリン酸化することによって,bglオペロンを否定的に調節する. このリン酸化はBglGを無活性化させ,β-グルコシドへの反応として遺伝子発現を制御する.
科学分野:
- 微生物学 微生物学とは
- 分子生物学は分子生物学である.
- 遺伝子規制 遺伝子規制
背景:
- E. coli bgl オペロンは,β-グルコシドの代謝を制御する.
- BglFはネガティブレギュレータとフォスフォトランスフェラーゼとして作用する.
- BglGは,陽性調節体および転写性アンチターミネーターとして機能します.
研究 の 目的:
- BglFとBglGの相互作用メカニズムを解明する.
- BglFがbglオペロン発現をどのように調節するかを理解するために.
- BglF-BglG相互作用におけるリン酸化の役割を調査する.
主な方法:
- 研究されたタンパク質とタンパク質の相互作用.
- 研究されたリン酸化および脱リン酸化イベント.
- 野生型および変異性BglG誘導体を使用した.
主要な成果:
- BglFは,フォスフォトランスフェラゼ系成分 (酵素I,HPr,フォスフェノルピルバート) によってリン酸化される.
- リン酸化BglFは,リン酸をβ-グルコシドまたはBglGに変換する.
- BglFは,BglG.をリン酸化し,無活性化することによって,bglオペロンを負の調節する.
結論:
- BglFの負の調節は,BglGをリン酸化し,その抗終止作用を阻害する.
- BglFによるBglGの脱リン酸化には,BglFとβ-グルコシドの両方が必要です.
- 提案されたメカニズムは,BglF-BglGのリン酸化状態に基づいたBglオペロン調節を説明しています.
関連する概念動画
Operons
Prokaryotes can control gene expression through operons—DNA sequences consisting of regulatory elements and clustered, functionally related protein-coding genes. Operons use a single promoter sequence to initiate transcription of a gene cluster (i.e., a group of structural genes) into a single mRNA molecule. The terminator sequence ends transcription. An operator sequence, located between the promoter and structural genes, prohibits the operon’s transcriptional activity if bound by a repressor...
Cell Specific Gene Expression
Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same parent cells. The differences in the cells can be attributed to the differential gene expression. Liver cells, whose functions include detoxification of blood, production of bile to metabolize fats, and synthesis of proteins essential for metabolism, must express a specific set of genes to perform their functions. Gene expression also varies with...
Prokaryotic Transcriptional Activators and Repressors
The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA.
Transcription of prokaryotic...
Transcription of prokaryotic...
Operons
Prokaryotes can control gene expression through operons—DNA sequences consisting of regulatory elements and clustered, functionally related protein-coding genes. Operons use a single promoter sequence to initiate transcription of a gene cluster (i.e., a group of structural genes) into a single mRNA molecule. The terminator sequence ends transcription. An operator sequence, located between the promoter and structural genes, prohibits the operon’s transcriptional activity if bound by a repressor...
Prokaryotic Transcriptional Activators and Repressors
The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA.
Transcription of prokaryotic...
Transcription of prokaryotic...
Inducible Operons: lac Operon
The lac operon in Escherichia coli is a model for understanding inducible gene regulation and metabolic flexibility. It integrates local control by lactose and global regulation through catabolite repression, enabling E. coli to preferentially metabolize glucose when available and switch to lactose utilization when glucose is scarce.Structure and Function of the lac OperonThe lac operon contains three structural genes: lacZ (β-galactosidase), lacY (lactose permease), and lacA (thiogalactoside...


