Co-occupancy of two Pumilio molecules on a single hunchback NRE.
RNA
; 15(6): 1029-35, 2009 Jun.
Article
en En
| MEDLINE
| ID: mdl-19372537
ABSTRACT
Pumilio controls a number of processes in eukaryotes, including the translational repression of hunchback (hb) mRNA in early Drosophila embryos. The Pumilio Puf domain binds to a pair of 32 nucleotide (nt) Nanos response elements (NRE1 and NRE2) within the 3' untranslated region of hb mRNA. Despite the elucidation of structures of human Pumilio Puf domain in complex with hb RNA elements, the nature of hb mRNA recognition remains unclear. In particular, the site that mediates regulation in vivo is significantly larger than the 8-10-nt RNA elements bound to single Puf molecules in crystal structures. Here we present biophysical and biochemical data that partially resolve the paradox. We show that each NRE is composed of two binding sites (Box A and Box B) and that two Puf domains can co-occupy a single NRE. The Puf domains have a higher affinity for the 3' Box B site than the 5' Box A site; binding to the intact NRE appears to be cooperative (at least in some experiments). We suggest that the 2 Pumilio1 NRE complex is the functional regulatory unit in vivo.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Factores de Transcripción
/
Proteínas de Unión al ARN
/
Proteínas de Drosophila
/
Secuencias Reguladoras de Ácido Ribonucleico
/
Proteínas de Unión al ADN
Tipo de estudio:
Prognostic_studies
Límite:
Animals
/
Humans
Idioma:
En
Revista:
RNA
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2009
Tipo del documento:
Article
País de afiliación:
Estados Unidos