Una arquitectura alternativa del sitio activo para la activación de O2 en el EgtB biosintético de ergotioneína de Chloracidobacterium thermophilum

Video Experimental Relacionado

Updated: Jan 27, 2026

Measurement of Larval Activity in the Drosophila Activity Monitor

Measurement of Larval Activity in the Drosophila Activity Monitor

Published on: April 30, 2015

Anja R Stampfli^1,2, Kristina V Goncharenko¹, Marcel Meury¹

¹Department of Chemistry , University of Basel , Mattenstrasse 24a , Basel 4002 , Switzerland.

Journal of the American Chemical Society

|March 19, 2019

Resumen

Las sulfóxidas sintasas, cruciales para la biosíntesis de la tiohistidina, tienen diversos sitios activos. La comparación de las estructuras de MthEgtB y CthEgtB revela configuraciones distintas para la activación del oxígeno, lo que ayuda a los estudios mecanicistas.

Área de la Ciencia:

La bioquímica
Enzimología
Biología estructural

Sus antecedentes:

Las sulfóxidas sintasas son enzimas de hierro no hemo que catalizan la formación de enlaces C-S en la biosíntesis de tiohistidina.
Los estudios anteriores se basaron en la estructura de Mycobacterium thermophilum EgtB (MthEgtB), lo que condujo a debates mecanicistas.
La biosíntesis de la ergotioneína involucra a las sulfóxidas como la EgtB.

Objetivo del estudio:

Proporcionar un modelo estructural alternativo para las sulfoxidas sintasas.
Investigar la base estructural de las diferentes especificidades del sustrato en los EgtB.
Clasificar los subtipos de EgtB en función de la arquitectura del sitio activo.

Principales métodos:

Cristalografía de rayos X de CthEgtB de Chloracidobacterium thermophilum.
Análisis estructural comparativo de CthEgtB y MthEgtB.
Análisis bioinformático para la clasificación EgtB.

Principales resultados:

Se determinó la estructura cristalina de CthEgtB, una sulfóxido sintasa que utiliza cisteína.
CthEgtB exhibe una configuración de sitio activo distinta para la unión y activación de oxígeno en comparación con MthEgtB.
Se estableció una clasificación de los EgtB en cinco subtipos basados en las características del sitio activo.

Conclusiones:

La diversidad del sitio activo en EgtBs ofrece una plataforma para la enzimología comparativa para dilucidar los mecanismos de la sulfoxida sintasa.
El surgimiento de múltiples soluciones estructurales para EgtB destaca la adaptabilidad evolutiva en la biosíntesis.
La comprensión de estas variaciones es clave para descifrar los complejos mecanismos catalíticos de las sulfoxidas.

Más Videos Relacionados

From a Natural Product to Its Biosynthetic Gene Cluster: A Demonstration Using Polyketomycin from Streptomyces diastatochromogenes Tü6028

From a Natural Product to Its Biosynthetic Gene Cluster: A Demonstration Using Polyketomycin from Streptomyces diastatochromogenes Tü6028

Published on: January 13, 2017

Detection of Neu1 Sialidase Activity in Regulating TOLL-like Receptor Activation

Detection of Neu1 Sialidase Activity in Regulating TOLL-like Receptor Activation

Published on: September 7, 2010

Videos de Conceptos Relacionados

Co-activators and Co-repressors

Co-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...

tRNA Activation

tRNA Activation

Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...

tRNA Activation

tRNA Activation

Activation Energy

Activation Energy

Activation energy is the minimum amount of energy necessary for a chemical reaction to move forward. The higher the activation energy, the slower the rate of the reaction. However, adding heat to the reaction will increase the rate, since it causes molecules to move faster and increase the likelihood that molecules will collide. The collision and breaking of bonds represents the uphill phase of a reaction and generates the transition state. The transition state is an unstable high-energy state...

Eukaryotic Transcription Activators

Eukaryotic 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...

Secondary Active Transport

Secondary Active Transport

One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme “pump” embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...