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Toeprinting Analysis of Translation Initiation Complex Formation on Mammalian mRNAs
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Una proteína de dedo estructuralmente similar a TFIIIA que se une exclusivamente al ARN 5S en Xenopusus
K E Joho1, M K Darby, E T Crawford
1Department of Embryology, Carnegie Institution of Washington, Baltimore, Maryland 21210.
Cell
|April 20, 1990
Resumen
Los ovocitos de Xenopus contienen una proteína de unión al ARN 5S (p43) que comparte similitudes estructurales con TFIIIA. A diferencia de TFIIIA, p43 se une exclusivamente al ARN 5S, no a sus genes.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Biología del desarrollo Biología del desarrollo.
- Xenopus laevis es objeto de investigación.
Sus antecedentes:
- Una proteína de unión al ARN 5S, p43, es abundante en los ovocitos de Xenopus.
- p43 es un componente de la partícula de almacenamiento de la ribonucleoproteína 42S.
Objetivo del estudio:
- Para clonar y secuenciar el ADNc p43 de Xenopus laevis y Xenopus borealis.
- Para comparar p43 con TFIIIA, otra proteína que se une al ARN 5S.
Principales métodos:
- clonación y secuenciación de ADNc de p43 y TFIIIA de Xenopus.
- Análisis de la secuencia de aminoácidos y comparación de homologías.
Principales resultados:
- p43 y TFIIIA comparten similitudes estructurales, incluidos nueve dedos de zinc.
- Siete dedos de zinc en p43 son idénticos en tamaño a los de TFIIIA.
- La homología de aminoácidos se concentra en residuos de dedos de zinc conservados.
- p43 se une exclusivamente al ARN 5S, mientras que TFIIIA se une tanto al ARN 5S como a sus genes.
Conclusiones:
- p43 es una proteína distinta que se une al ARN 5S con una función específica de unión al ARN.
- Las similitudes estructurales sugieren un origen evolutivo común o una relación funcional entre p43 y TFIIIA.
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