Video Experimental Relacionado
Updated: Jun 20, 2026
07:44
High-throughput Purification of Affinity-tagged Recombinant Proteins
Published on: August 26, 2012
Un factor de transcripción de ARN polimerasa II de Drosophila contiene una actividad de unión al ADN específica de la
Cell
|February 1, 1984
Resumen
Los investigadores purificaron parcialmente el factor de transcripción B de Drosophila, revelando un componente de unión al ADN esencial para la iniciación precisa de la ARN polimerasa II. Este factor se une a una región específica del ADN alrededor del sitio de inicio de la transcripción.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Genética La genética.
- La bioquímica es la bioquímica.
Sus antecedentes:
- La iniciación precisa de la transcripción por la ARN polimerasa II de Drosophila requiere múltiples factores de transcripción.
- Dos factores distintos, A y B, son necesarios para la precisión de la transcripción in vitro.
Objetivo del estudio:
- Para purificar y caracterizar parcialmente el factor de transcripción B.
- Para investigar las propiedades de unión al ADN del factor B.
Principales métodos:
- Purificación cromatográfica del factor de transcripción B.
- Los ensayos de huellas de ADN utilizan DNase I.
- Análisis de la especificidad de unión al ADN.
Principales resultados:
- Se identificó un componente de unión al ADN específico de la secuencia dentro de la fracción purificada del factor B.
- Este componente se une a una región de 65 bp que abarca la caja TATA, el sitio de inicio de la transcripción y la región líder de los genes de histona H3, H4 y actina 5C.
- La unión se observó independientemente de la ARN polimerasa II.
Conclusiones:
- El factor B contiene un elemento de unión al ADN específico de la secuencia crucial para el inicio de la transcripción.
- Esta actividad de unión es una característica clave del papel del factor B en la regulación de la transcripción génica.
Videos de Conceptos Relacionados
02:16Transcription Factors
Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...
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...
02:42Eukaryotic 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...
01:47Transcription Initiation
Initiation is the first step of transcription in eukaryotes. Prokaryotic RNA Polymerase (RNAP) can bind to the template DNA and start transcribing. On the other hand, transcription in eukaryotes requires additional proteins, called transcription factors, to first bind to the promoter region in the DNA template. This binding helps recruit the specific RNAP that can assemble on the DNA and start transcription.
The promoters and enhancers and their accessory proteins allow tight regulation of...
The promoters and enhancers and their accessory proteins allow tight regulation of...
01:30General Transcription Factors
Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...
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...