Video Experimental Relacionado
Updated: Jun 23, 2026
12:24
DNA-affinity-purified Chip (DAP-chip) Method to Determine Gene Targets for Bacterial Two component Regulatory Systems
Published on: July 21, 2014
Bases estructurales para el control alostérico del regulador de la transcripción CcpA por la fosfoproteína
Maria A Schumacher1, Gregory S Allen, Marco Diel
1Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland 97239, USA.
Cell
|September 17, 2004
Resumen
La represión de los catabolitos de carbono (CCR) en las bacterias utiliza CcpA regulado por HPr-Ser46-P. Los estudios estructurales revelan un nuevo mecanismo alostérico para la activación de la unión al ADN, crucial para el metabolismo del carbono bacteriano y la supervivencia.
Área de la Ciencia:
- Biología molecular bacteriana Biología molecular bacteriana
- Biología estructural Biología estructural.
- El metabolismo microbiano es el metabolismo microbiano.
Sus antecedentes:
- La represión de los catabolitos de carbono (CCR, por sus siglas en inglés) es un mecanismo clave de las bacterias para detectar el medio ambiente.
- CcpA es el regulador maestro de la transcripción de CCR en las bacterias gram-positivas.
- La CcpA funciona con la fosfoproteína HPr-Ser46-P como un corepresor alostérico.
Objetivo del estudio:
- Para dilucidar la base estructural de la represión de los catabolitos de carbono mediada por CcpA.
- Para comprender el mecanismo de activación alostérica de la unión al ADN de CcpA.
- Para revelar la interacción entre CcpA, HPr-Ser46-P y el ADN.
Principales métodos:
- Cristalografía de rayos X con rayos X.
- Análisis estructural de los complejos apoCcpA y CcpA-ADN.
- Pruebas bioquímicas de ensayos.
Principales resultados:
- Se determinaron las estructuras de Bacillus megaterium apoCcpA y un complejo de CcpA- ((HPr-Ser46-P) -ADN.
- HPr-Ser46-P media una nueva activación de unión al ADN alostérico de dos componentes.
- Este mecanismo implica la rotación del subdominio CcpA y la reubicación de Thr61, lo que permite la unión al ADN.
- Se aclararon las interacciones específicas con los residuos HPr-Ser46-P Ser46-P y His15.
Conclusiones:
- El estudio revela un nuevo mecanismo alostérico para la activación de la unión al ADN de CcpA por HPr-Ser46-P.
- Las ideas estructurales explican cómo la CcpA regula las vías del metabolismo del carbono.
- Este trabajo profundiza la comprensión de la detección ambiental bacteriana y la adaptación metabólica.
Videos de Conceptos Relacionados
02:04Covalently Linked Protein Regulators
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
These groups modify specific amino acids in a protein.
02:36RNA 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...
01:58Cell 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...
01:58Prokaryotic 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...
02:04Co-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...
01:58Prokaryotic 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...