The effects of disrupting 5S RNA helical structures on the binding of Xenopus transcription factor IIIA.
AUTOR(ES)
You, Q M
RESUMO
Block mutations were constructed in helical stems II, III, IV and V of Xenopus laevis oocyte 5S RNA. The affinities of these mutants for binding to transcription factor IIIA (TFIIIA) were determined using a nitrocellulose filter binding assay. Mutations in stems III and IV had little or no effect on the binding affinity of TFIIIA for 5S RNA. However, single mutants in stems II and V (positions 16-21, 57-62, 71-72, and 103-104) which disrupt the double helix, reduce the binding of TFIIIA by a factor of two to three fold. In contrast, double mutants (16-21/57-62, 71-72/103-104) which restore the helical structure of these stems, but with altered sequences, fully restore the TFIIIA binding affinity. The experiments reported here indicate that the double helical structures of stems II and V, but not the sequences, are required for optimal TFIIIA binding.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=332123Documentos Relacionados
- Defining the binding site of Xenopus transcription factor IIIA on 5S RNA using truncated and chimeric 5S RNA molecules.
- Structural requirements for the interaction of 5S rRNA with the eukaryotic transcription factor IIIA.
- Structural analysis of a triple complex between the histone octamer, a Xenopus gene for 5S RNA and transcription factor IIIA.
- 5S rRNA gene transcription factor IIIA alters the helical configuration of DNA.
- Xenopus transcription factor IIIA binds primarily at junctions between double helical stems and internal loops in oocyte 5S RNA.