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Las quinonas como la señal redox para el sistema de dos componentes del arco de las bacterias
D Georgellis1, O Kwon, E C Lin
1Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA.
Science (New York, N.Y.)
|June 26, 2001
Resumen
El sistema Arc en E. coli vincula la respiración y la expresión génica. Las quinonas oxidadas inhiben la actividad de la cinasa del sensor ArcB durante el crecimiento aeróbico, regulando los operones metabólicos.
Área de la Ciencia:
- Microbiología Microbiología.
- Biología Molecular Biología Molecular
- La bioquímica es la bioquímica.
Sus antecedentes:
- El sistema de dos componentes de Arc regula la adaptación de Escherichia coli a las diferentes condiciones respiratorias.
- Las kinasas sensoriales ArcB y los reguladores de la transcripción ArcA operan para controlar el metabolismo respiratorio y fermentativo.
Objetivo del estudio:
- Investigar el mecanismo regulador del sistema de transducción de señales Arc en respuesta a condiciones aeróbicas.
- Para identificar las moléculas de señalización que inhiben la actividad de ArcB durante la aerobiosis.
Principales métodos:
- Investigó la autofosforilación de la cinasa del sensor ArcB.
- Analizó el efecto de los portadores de electrones de quinona en la actividad de ArcB.
- Estudió el impacto en la regulación transcripcional de los operones metabólicos.
Principales resultados:
- Los portadores de electrones de quinona oxidados inhiben directamente la autophosphorylation de la cinasa del sensor ArcB.
- Esta inhibición se produce específicamente durante las condiciones de crecimiento aeróbico.
- El sistema Arc vincula efectivamente la cadena de transporte de electrones a los cambios en la expresión génica.
Conclusiones:
- El sistema de transducción de señales Arc proporciona un vínculo directo entre la cadena de transporte de electrones y la expresión génica.
- Las quinonas oxidadas actúan como señales negativas para modular la actividad de ArcB, permitiendo respuestas metabólicas adaptativas en E. coli.
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