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Estructura y secuestro del sustrato en la proteína transportadora de peptídiles tipo II de pioluteorina PltL

Matt J Jaremko¹, D John Lee¹, Stanley J Opella¹

¹Department of Chemistry and Biochemistry, University of California, San Diego , 9500 Gilman Drive, La Jolla, California 92093-0358, United States.

Journal of the American Chemical Society

|September 5, 2015

Resumen

Este estudio revela cómo las proteínas transportadoras de péptidos de pirrol (PCP) se unen a sustratos de pirrol, cruciales para la creación de productos naturales bioactivos a través de las sintetasas de péptidos no ribosómicos (NRPS). Los hallazgos destacan los mecanismos conservados y el secuestro de sustratos en las vías de NRPS.

Área de la Ciencia:

La bioquímica
Biología molecular
Biología estructural

Sus antecedentes:

Las sintetasas de péptidos no ribosómicos tipo II (NRPS) sintetizan productos naturales bioactivos complejos.
Las fracciones de pirrolo, a menudo derivadas de la oxidación de la prolina, son componentes clave en muchos productos naturales.
Las proteínas transportadoras de peptídiles (PCP) son esenciales para el enlace y la modificación de sustratos en las vías NRPS.

Objetivo del estudio:

Aclarar el papel estructural de los PCP de tipo II productores de pirrolo en las interacciones de sustrato y proteína.
Comprender el mecanismo de formación, modificación e incorporación de la fracción de pirrolo.
Investigar el secuestro y la regulación de sustratos dentro de los sistemas NRPS.

Principales métodos:

Espectroscopia de resonancia magnética nuclear (RMN) en fase de solución.
Análisis estructural de los análogos de pirrolo atados al PltL PCP.
Análisis del Efecto Nuclear Overhauser (NOE) para determinar los motivos de unión.

Principales resultados:

Se han identificado las principales interacciones de residuos entre las hélices II y III de PltL y la fracción de pirrolo unida.
Reveló un motivo de unión conservado para sustratos de pirrol dentro de la hendidura de PCP.
Se observó una conformación única de la hélice III, lo que sugiere el secuestro del sustrato por el PCP.

Conclusiones:

Los hallazgos estructurales sugieren un mecanismo conservado para la biosíntesis de la fracción de pirrolo a través de diferentes vías de NRPS.
El motivo de unión de pirrol identificado facilita el posicionamiento preciso del sustrato.
El secuestro del sustrato mediado por PCP es importante para regular la actividad de NRPS tipo II.

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