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Genome-wide Analysis of Aminoacylation (Charging) Levels of tRNA Using Microarrays
Published on: June 18, 2010
La pirrolisina codificada por UAG en las arqueas: carga de un tRNA especializado en la decodificación de UAG
Gayathri Srinivasan1, Carey M James, Joseph A Krzycki
1Department of Microbiology, Ohio State University, Columbus, OH 43210, USA.
Science (New York, N.Y.)
|May 25, 2002
Resumen
La pirrolisina, el 22o aminoácido, está codificada por el codón UAG en Methanosarcina barkeri. Su traducción implica un RNA de transferencia único (tRNA) y una aminoacil-tRNA sintetasa, lo que permite la incorporación de pirrolisina.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Molecular Biología Molecular
- Genética La genética.
Sus antecedentes:
- La pirrolisina es un derivado de la lisina.
- Está codificado por el codón UAG en los genes de la metilamina metiltransferasa de Methanosarcina barkeri.
- El gen pylT codifica un ARN de transferencia (ARNt) con un anticódono CUA, y el gen pylS codifica una aminoacil-ARNt sintetasa única.
Objetivo del estudio:
- Para investigar el mecanismo de incorporación de la pirrolisina.
- Para identificar los componentes genéticos involucrados en la traducción de la pirrolisina.
- Para confirmar la pirrolisina como el 22o aminoácido codificado genéticamente.
Principales métodos:
- Identificación y caracterización de genes (pylT y pylS).
- Análisis de la actividad de la aminoacil-tRNA sintetasa.
- Investigación de la carga de tRNA con lisina.
Principales resultados:
- La pirrolisina está codificada por el codón UAG.
- Un nuevo tRNA (pylT) y la aminoacil-tRNA sintetasa (pylS) están involucrados en la traducción de la pirrolisina.
- Los homólogos de estos genes existen en una bacteria Gram-positiva.
- La carga de tRNA (CUA) con lisina es un paso clave.
Conclusiones:
- La pirrolisina es el 22o aminoácido natural codificado genéticamente.
- El sistema pylS-pylT facilita la traducción de los codones UAG como pirrolisina en los metanógenos.
- Este descubrimiento amplía el código genético conocido.
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