Video Experimental Relacionado

Updated: May 1, 2026

Assessment of Immunologically Relevant Dynamic Tertiary Structural Features of the HIV-1 V3 Loop Crown R2 Sequence by ab initio Folding

Assessment of Immunologically Relevant Dynamic Tertiary Structural Features of the HIV-1 V3 Loop Crown R2 Sequence by ab initio Folding

Published on: September 16, 2010

Estructura del dominio de la ADN desaminasa del factor de restricción del VIH-1 APOBEC3G

Kuan-Ming Chen¹, Elena Harjes, Phillip J Gross

¹Department of Biochemistry, Molecular Biology and Biophysics, [of Minnesota, Minneapolis, Minnesota 55455, USA.

|February 22, 2008

Resumen

La proteína humana APOBEC3G, una enzima antiviral, tiene una estructura recién determinada. Esta estructura revela cómo se une al ADN para inhibir virus como el VIH-1.

Área de la Ciencia:

La bioquímica es la bioquímica.
Biología Estructural Biología estructural.
Virología Virología.

Sus antecedentes:

APOBEC3G (enzima de edición de ARN-mensajero de apolipoproteína B, 3G de tipo polipéptido catalítico) es una desaminasa de ADN humano con propiedades antivirales contra retrovirus como el VIH-1.
Su actividad antiviral a menudo es superada por factores virales, como el VIH-1 Vif, lo que lleva a la degradación de APOBEC3G.
APOBEC3G pertenece a una familia de desaminasas de citosina de polinucleótidos, incluidas APOBEC1 y AID, que tienen funciones fisiológicas distintas.

Objetivo del estudio:

Para determinar la estructura de la solución del dominio catalítico humano APOBEC3G.
Para dilucidar el mecanismo de unión y catálisis del ADN por APOBEC3G.
Proporcionar información sobre las interacciones de APOBEC3G con proteínas virales como el VIH-1 Vif.

Principales métodos:

Espectroscopia de Resonancia Magnética Nuclear (RMN) para la determinación de la estructura de la solución.
Experimentos de titulación de ADN utilizando RMN.
El modelado computacional.
Análisis filogenético de la conservación.
Ensayos de actividad enzimática basados en Escherichia coli.

Principales resultados:

Se determinó la estructura de solución del dominio catalítico APOBEC3G, revelando una disposición de cinco hélices alfa sobre una plataforma hidrofóbica de cinco hebras beta.
Se identificaron dos hélices alfa que forman el sitio activo coordinador del zinc.
Se propuso un modelo de unión al ADN, lo que sugiere que los residuos cargados positivamente en una posición de "borde" de la citosina objetivo para la catálisis.
La estructura y el modelo de unión al ADN fueron apoyados por RMN, modelado computacional, datos filogenéticos y ensayos funcionales.

Conclusiones:

La estructura determinada del dominio catalítico APOBEC3G proporciona una base molecular para su ADN deaminasa y sus actividades antivirales.
El modelo propuesto de unión al ADN ofrece información sobre cómo APOBEC3G reconoce e interactúa con su sustrato de ADN.
Comprender la estructura APOBEC3G puede facilitar la investigación sobre las funciones de los miembros de la familia relacionados y sus interacciones con las proteínas virales, lo que podría ayudar en el desarrollo de estrategias antivirales.

Más Videos Relacionados

Determining 3'-Termini and Sequences of Nascent Single-Stranded Viral DNA Molecules during HIV-1 Reverse Transcription in Infected Cells

Determining 3'-Termini and Sequences of Nascent Single-Stranded Viral DNA Molecules during HIV-1 Reverse Transcription in Infected Cells

Published on: January 30, 2019

Probing The Structure And Dynamics Of Nucleosomes Using Atomic Force Microscopy Imaging

Probing The Structure And Dynamics Of Nucleosomes Using Atomic Force Microscopy Imaging

Published on: January 31, 2019

Videos de Conceptos Relacionados

RNA Editing

RNA Editing

RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the...

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...

Exon Recombination

Exon Recombination

The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon...

Nucleic Acid Structure

Nucleic Acid Structure

The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage.
DNA Structure
DNA...

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...

Inhibitors of Viral Protein Synthesis

Inhibitors of Viral Protein Synthesis

Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and...