Video Experimental Relacionado

Updated: Apr 12, 2026

Bacterial Artificial Chromosomes: A Functional Genomics Tool for the Study of Positive-strand RNA Viruses

Bacterial Artificial Chromosomes: A Functional Genomics Tool for the Study of Positive-strand RNA Viruses

Published on: December 29, 2015

Conocimientos estructurales sobre la replicación del Bunyavirus y su regulación por el promotor de ARNv

Piotr Gerlach¹, Hélène Malet¹, Stephen Cusack¹

¹European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, CS90181, 38042 Grenoble Cedex 9, France; Unit of Virus Host-Cell Interactions (UMI 3265), University Grenoble Alpes-EMBL-CNRS, 71 Avenue des Martyrs, CS90181, 38042 Grenoble Cedex 9, France.

|May 26, 2015

Resumen

Las perspectivas estructurales en las polimerasas del virus de ARN de cadena negativa segmentada (sNSV) revelan cómo sintetizan el ARN viral (ARNv). Las estructuras polimerasas del La Crosse orthobunyavirus (LACV) elucidan los mecanismos de unión y replicación del ARN, ayudando al desarrollo de inhibidores.

Área de la Ciencia:

Biología estructural Biología estructural.
Virología Virología.
Mecanismos moleculares de la síntesis del ARN

Sus antecedentes:

Los virus de ARN de cadena negativa segmentada (sNSV) causan enfermedades humanas significativas.
La síntesis del ARN viral (ARNv) está orquestada por las polimerasas virales dentro de las partículas de ribonucleoproteína (RNP).
Comprender la función de la sNSV polimerasa es crucial para el desarrollo de terapias antivirales.

Objetivo del estudio:

Para determinar las estructuras de resolución atómica de La Crosse orthobunyavirus (LACV) polimerasa.
Para dilucidar el mecanismo de la transcripción y replicación del ARNv por sNSV polimerasas.
Proporcionar información para el desarrollo de nuevos inhibidores de la replicación antiviral.

Principales métodos:

Microscopía cryoelectrónica (cryo-EM) para la estructura de la polimerasa apo-LACV.
Cristalografía de rayos X para la estructura de la polimerasa LACV ligada al ARNv.
Análisis estructural de la unión al ARNv y la conformación del sitio activo.

Principales resultados:

Se determinaron las estructuras de resolución atómica de la polimerasa LACV ligada al apo y al ARNv.
Las extremidades 3' y 5' del ARNv se unen a sitios distintos de la polimerasa.
El extremo 5' del ARNv, como un bucle del tallo, regula alostericamente los bucles del sitio activo.
Se identificaron diferentes túneles de salida de plantillas y productos, lo que permite un modelo de replicación.
La polimerasa LACV comparte similitudes estructurales y de unión de ARNv con la polimerasa de la influenza, lo que sugiere un origen evolutivo común.

Conclusiones:

Las estructuras proporcionan una visión sin precedentes de la síntesis de ARN sNSV.
Se propone un modelo detallado para la replicación dirigida por plantillas dentro de los RNP.
Las características conservadas sugieren un origen evolutivo común y un mecanismo para todas las polimerasas de sNSV.
Estos hallazgos facilitarán el diseño de inhibidores de la replicación contra los SNSVs patógenos.

Más Videos Relacionados

Development of a Hepatitis B Virus Reporter System to Monitor the Early Stages of the Replication Cycle

Development of a Hepatitis B Virus Reporter System to Monitor the Early Stages of the Replication Cycle

Published on: February 1, 2017

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

Videos de Conceptos Relacionados

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...

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...

Size and Structure of Viral Genomes

Size and Structure of Viral Genomes

Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. These genomes consist of either DNA or RNA and may be linear or circular. Additionally, they can be single-stranded or double-stranded, with each configuration affecting how the virus propagates within a host. RNA viruses, for instance, generally have smaller genomes than DNA viruses, a factor that contributes to their high mutation rates and...

Bacterial RNA Polymerase

Bacterial RNA Polymerase

Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity.
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...

Leaky Scanning

Leaky Scanning

During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R...

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: