Upstream binding factor stabilizes Rib 1, the TATA-binding-protein-containing Xenopus laevis RNA polymerase I transcription factor, by multiple protein interactions in a DNA-independent manner.
AUTOR(ES)
Bodeker, M
RESUMO
Initiation of RNA polymerase I transcription in Xenopus laevis requires Rib 1 and upstream binding factor (UBF). UBF and Rib 1 combine to form a stable transcription complex on the Xenopus ribosomal gene promoter. Here we show that Rib 1 comprises TATA-binding protein (TBP) and TBP-associated factor components. Thus, Rib 1 is the Xenopus equivalent of mammalian SL 1. In contrast to SL 1, Rib 1 is an unstable complex that readily dissociates into TBP and associated components. We identify a novel function for UBF in stabilizing Rib 1 by multiple protein interactions. This stabilization occurs in solution in a DNA-independent manner. These results may partially explain the difference in UBF requirement between Xenopus and mammalian systems.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=231556Documentos Relacionados
- Mitotic regulation of a TATA-binding-protein-containing complex.
- Virion DNA-independent RNA polymerase from Saccharomyces cerevisiae.
- TATA-box DNA binding activity and subunit composition for RNA polymerase III transcription factor IIIB from Xenopus laevis.
- A DNA-binding protein is required for termination of transcription by RNA polymerase I in Xenopus laevis.
- The Xenopus laevis poly(A) binding protein is composed of multiple functionally independent RNA binding domains.