Structural basis for transcriptional start site control of HIV-1 RNA fate.
Science
; 368(6489): 413-417, 2020 04 24.
Article
en En
| MEDLINE
| ID: mdl-32327595
ABSTRACT
Heterogeneous transcriptional start site usage by HIV-1 produces 5'-capped RNAs beginning with one, two, or three 5'-guanosines (Cap1G, Cap2G, or Cap3G, respectively) that are either selected for packaging as genomes (Cap1G) or retained in cells as translatable messenger RNAs (mRNAs) (Cap2G and Cap3G). To understand how 5'-guanosine number influences fate, we probed the structures of capped HIV-1 leader RNAs by deuterium-edited nuclear magnetic resonance. The Cap1G transcript adopts a dimeric multihairpin structure that sequesters the cap, inhibits interactions with eukaryotic translation initiation factor 4E, and resists decapping. The Cap2G and Cap3G transcripts adopt an alternate structure with an elongated central helix, exposed splice donor residues, and an accessible cap. Extensive remodeling, achieved at the energetic cost of a G-C base pair, explains how a single 5'-guanosine modifies the function of a ~9-kilobase HIV-1 transcript.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Caperuzas de ARN
/
ARN Viral
/
Regulación Viral de la Expresión Génica
/
VIH-1
/
Emparejamiento Base
/
Sitio de Iniciación de la Transcripción
Límite:
Humans
Idioma:
En
Revista:
Science
Año:
2020
Tipo del documento:
Article
País de afiliación:
Estados Unidos