Video Experimental Relacionado

Updated: Jan 2, 2026

In Vitro Transcribed RNA-based Luciferase Reporter Assay to Study Translation Regulation in Poxvirus-infected Cells

In Vitro Transcribed RNA-based Luciferase Reporter Assay to Study Translation Regulation in Poxvirus-infected Cells

Published on: May 1, 2019

Bases estructurales de la transcripción del virus de la viruela: complejos de transcripción y tapa de vacunas

Hauke S Hillen¹, Julia Bartuli², Clemens Grimm²

¹Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.

|December 14, 2019

Resumen

Los poxvirus sintetizan ARN mensajeros (ARNm) utilizando las polimerasas de ARN viral (ARNpv) y las enzimas de captura. Este estudio revela las estructuras de microscopía criolectrónica de estos complejos, explicando la síntesis y modificación del ARNm.

Área de la Ciencia:

Virología
Biología estructural
Biología molecular

Sus antecedentes:

Los poxvirus dependen de las polimerasas de ARN codificadas por el virus (vRNAPs) y los factores de procesamiento de ARN para la síntesis y el cierre en el citoplasma del huésped.
En trabajos anteriores se informó de las estructuras de núcleos y complejos de Vaccinia poxvirus vRNAP.

Objetivo del estudio:

Presentar las estructuras de cryoelectron microscopy (cryo-EM) de Vaccinia vRNAP en la transcripción de la elongación y los complejos de capping de co-transcripción.
Para aclarar la base estructural para la síntesis de ARN del virus de la viruela y la modificación co-transcripcional.

Principales métodos:

Para determinar las estructuras de los complejos de Vaccinia vRNAP se utilizó la criomicroscopia electrónica.
Se realizaron comparaciones estructurales para analizar los reordenamientos durante la transcripción y el encapsulamiento.

Principales resultados:

Se obtuvieron estructuras de Vaccinia vRNAP en complejos de elongación y de tapa de co-transcripción.
La enzima de tapa viral (CE) forma dos módulos móviles que interactúan con la polimerasa alrededor del túnel de salida de ARN.
Se visualizó la progresión del ARN desde el sitio activo del vRNAP hasta el sitio activo de la trifosfatasa CE.
Se observaron reordenamientos a gran escala en la maquinaria de transcripción durante la transición de la iniciación a la tapa y el alargamiento.

Conclusiones:

Las estructuras revelan cómo los poxvirus sintetizan y modifican co-transcripcionalmente su ARN.
Comprender estos mecanismos proporciona una visión de la maquinaria molecular de la expresión génica del virus de la viruela.

Palabras clave:

La ARN polimerasa dependiente del ADN Poxviridae y sus derivados La ARN polimerasa Las vacunas Enzima de encapsulación Microscopía electrónica criogénica Crio-EM alargamiento La estructura transcripción

Más Videos Relacionados

Vaccinia Virus Infection & Temporal Analysis of Virus Gene Expression: Part 2

Vaccinia Virus Infection & Temporal Analysis of Virus Gene Expression: Part 2

Published on: April 10, 2009

Vaccinia Virus Infection & Temporal Analysis of Virus Gene Expression: Part 1

Vaccinia Virus Infection & Temporal Analysis of Virus Gene Expression: Part 1

Published on: April 8, 2009

Videos de Conceptos Relacionados

Viral Structure

Viral Structure

Viruses are extraordinarily diverse in shape and size, but they all have several structural features in common. All viruses have a core that contains a DNA- or RNA-based genome. The core is surrounded by a protective coat of proteins called the capsid. The capsid is composed of subunits called capsomeres. The capsid and genome-containing core are together known as the nucleocapsid.

Retrovirus Life Cycles

Retrovirus Life Cycles

Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the...

RNA Polymerase II Accessory Proteins

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...

RNA Polymerase II Accessory Proteins

RNA Polymerase II Accessory Proteins

Bacterial Transcription

Bacterial Transcription

RNA polymerase (RNAP) carries out DNA-dependent RNA synthesis in both bacteria and eukaryotes. Bacteria do not have a membrane-bound nucleus. So, transcription and translation occur simultaneously, on the same DNA template.
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:

Viruses with RNA Genomes

Viruses with RNA Genomes

RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger...