Short-Range DNA Looping by the Xenopus HMG-Box Transcription Factor, xUBF
Abstract
Xenopus UBF (xUBF) interacts with DNA by way of multiple HMG-box domains. When xUBF binds to the ribosomal promoter, the carboxyl-terminal acidic tail and amino-terminal HMG-box interact. Binding also leads to negative DNA supercoiling and the formation of a disk-like structure, the enhancesome. Within the enhancesome, an xUBF dimer makes a low-density protein core around which DNA is looped into a single 180-base pair turn, probably by in-phase bending. The enhancesome structure suggests a mechanism for xUBF-dependent recruitment of the TATA box-binding protein complex without direct interaction between the two factors.
- Publication:
-
Science
- Pub Date:
- May 1994
- DOI:
- 10.1126/science.8178172
- Bibcode:
- 1994Sci...264.1134B