Video Experimental Relacionado
Updated: Jun 6, 2026
13:47
Lentiviral Vector Platform for the Efficient Delivery of Epigenome-editing Tools into Human Induced Pluripotent Stem Cell-derived Disease Models
Published on: March 29, 2019
Mecanismo de la unión específica al ADN mediada por el corepresor por el represor de purina
M A Schumacher1, K Y Choi, F Lu
1Department of Biochemistry and Molecular Biology, Oregon Health Sciences University, Portland 97201-3098, USA.
Cell
|October 6, 1995
Resumen
Los efectores de moléculas pequeñas modulan la afinidad de las proteínas de unión al ADN. La eliminación del corepressor hace que el purine repressor.
Área de la Ciencia:
- Biología Estructural Biología estructural.
- Biología Molecular Biología Molecular
- La bioquímica es la bioquímica.
Sus antecedentes:
- Los efectores de moléculas pequeñas modulan comúnmente la afinidad de las proteínas de unión al ADN en procariotas y eucariotas.
- Los mecanismos de la regulación alostérica inducida por efectores de la unión del ADN por los dominios de proteínas distales siguen siendo estructuralmente poco comprendidos.
Objetivo del estudio:
- Para dilucidar el mecanismo estructural de la unión del ADN modulado por el efector en el represor de purinas.
- Para entender cómo la unión del corepresor influye en la interacción del ADN en esta familia de represores.
Principales métodos:
- Determinó la estructura cristalina del represor de purina unido a un operador de corepressor y purF en estudios iniciales.
- Determinó la estructura cristalina del dominio de unión al núcleo-presor libre del núcleo-presor del represor de purina a una resolución de 2.2 Å.
Principales resultados:
- El análisis estructural reveló cambios conformacionales significativos en el bolsillo de unión del núcleo-presor en el estado no ligado.
- Cada subunidad se abrió girando hasta 23 grados tras la extracción del compresor central.
- Esta rotación desactiva las hélices de bisagra menores que unen las ranuras, lo que lleva a la disociación del ADN represor.
Conclusiones:
- El represor de purina sufre cambios conformacionales sustanciales en la unión y liberación del corepresor.
- La regulación alostérica de la unión al ADN está mediada por movimientos de dominio a gran escala.
- Esto proporciona una base estructural para la comprensión de la unión de ADN modulado por efector en represores.
Videos de Conceptos Relacionados
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...
02:13Cooperative Binding of Transcription Regulators
Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form dimers that...
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...
01:52Eukaryotic Transcription Inhibitors
Certain biochemical processes, such as embryonic development and cell growth regulation, depend on the repression of specific genes. DNA binding proteins known as eukaryotic transcription inhibitors regulate the repression of gene expression in eukaryotes. The presence of these inhibitors at the required location and time in the cell is triggered by the presence of hormones and additional signals from other cells.
Eukaryotic transcription inhibitors usually contain two distinct domains, a DNA...
Eukaryotic transcription inhibitors usually contain two distinct domains, a DNA...
02:13Cooperative Binding of Transcription Regulators
Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form dimers that...
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...