Video Experimental Relacionado

Updated: Feb 10, 2026

In Vitro Analysis of E3 Ubiquitin Ligase Function

In Vitro Analysis of E3 Ubiquitin Ligase Function

Published on: May 14, 2021

Conocimientos sobre la catálisis y la función de la ubiquitinación de serina ligada al fosforibosilo

Sissy Kalayil^1,2, Sagar Bhogaraju^1,2, Florian Bonn¹

¹Institute of Biochemistry II, Goethe University Frankfurt - Medical Faculty, University Hospital, Frankfurt am Main, Germany.

|May 26, 2018

Resumen

Legionella pneumophila y sus derivados

Área de la Ciencia:

Biología molecular
Biología estructural
Bacteriología

Sus antecedentes:

La ubiquitinación convencional utiliza ATP para vincular la ubiquitina con las proteínas del sustrato.
La Legionella pneumophila patogénica utiliza NAD+ para la ubiquitinación de serina a través de los efectores SidE.
Se desconoce el mecanismo catalítico de la ubiquitinación de serina por efectores SidE.

Objetivo del estudio:

Para aclarar la arquitectura molecular del núcleo catalítico SdeA.
Para comprender el mecanismo de ubiquitinación de serina por SdeA.
Identificar los sustratos de SdeA y su papel en la patogénesis bacteriana.

Principales métodos:

Cristalografía de rayos X para determinar la estructura del núcleo catalítico del SdeA.
Ensayos bioquímicos para caracterizar la actividad enzimática y la especificidad del sustrato.
Estudios de infección con mutantes de Legionella pneumophila.

Principales resultados:

La estructura del núcleo catalítico de SdeA revela dominios de mono-ADP-ribosiltransferasa (mART) y fosfodiesterasa (PDE).
Dos sitios catalíticos distintos median un proceso de ubiquitinación de serina en dos pasos.
Los polipéptidos desordenados con residuos hidrofóbicos cerca de la serina son sustratos preferidos de SdeA.
Los efectos patógenos de SdeA dependen de la ubiquitinación del sustrato, no de la modificación del grupo de ubiquitina.

Conclusiones:

El estudio revela la estructura y el mecanismo de la ubiquitinación de serina mediada por SdeA.
SdeA utiliza una plataforma catalítica mART-PDE única para la transferencia de fosforibosil-ubiquitina.
La ubiquitinación del sustrato por SdeA es crítica para la patogénesis de Legionella.

Más Videos Relacionados

Functional Characterization of RING-Type E3 Ubiquitin Ligases In Vitro and In Planta

Functional Characterization of RING-Type E3 Ubiquitin Ligases In Vitro and In Planta

Published on: December 5, 2019

Profiling Ubiquitin and Ubiquitin-like Dependent Post-translational Modifications and Identification of Significant Alterations

Profiling Ubiquitin and Ubiquitin-like Dependent Post-translational Modifications and Identification of Significant Alterations

Published on: November 7, 2019

Videos de Conceptos Relacionados

Covalently Linked Protein Regulators

Covalently Linked Protein Regulators

Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein....

Catalysis

Catalysis

The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.

Introduction to Mechanisms of Enzyme Catalysis

Introduction to Mechanisms of Enzyme Catalysis

For many years, scientists thought that enzyme-substrate binding took place in a simple "lock-and-key" fashion. This model stated that the enzyme and substrate fit together perfectly in one instantaneous step. However, current research supports a more refined view scientists call induced fit. The induced-fit model expands upon the lock-and-key model by describing a more dynamic interaction between enzyme and substrate. As the enzyme and substrate come together, their interaction causes...

X-linked Traits

X-linked Traits

In most mammalian species, females have two X sex chromosomes and males have an X and Y. As a result, mutations on the X chromosome in females may be masked by the presence of a normal allele on the second X. In contrast, a mutation on the X chromosome in males more often causes observable biological defects, as there is no normal X to compensate. Trait variations arising from mutations on the X chromosome are called “X-linked”.

Functional Groups

Functional Groups

Functional groups are a group of atoms with characteristic properties, which when linked to the carbon skeleton of a molecule, alter the properties of that molecule. For example, the presence of certain functional groups on a molecule will make them hydrophilic, whereas others will make them hydrophobic. These functional groups are an indispensable part of organic chemistry and important components of biological molecules, such as carbohydrates, proteins, lipids, and nucleic acids. Each...

Sex-linked Disorders

Sex-linked Disorders

Like autosomes, sex chromosomes contain a variety of genes necessary for normal body function. When a mutation in one of these genes results in biological deficits, the disorder is considered sex-linked.