Bazett-Jones D P, Leblanc B, Herfort M, Moss T
Department of Medical Biochemistry and Anatomy, Faculty of Medicine, Health Sciences Center, University of Calgary, Alberta, Canada.
Science. 1994 May 20;264(5162):1134-7. doi: 10.1126/science.8178172.
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.
非洲爪蟾UBF（xUBF）通过多个HMG盒结构域与DNA相互作用。当xUBF与核糖体启动子结合时，其羧基末端酸性尾巴和氨基末端HMG盒相互作用。这种结合还会导致DNA负超螺旋以及形成一种盘状结构，即增强体。在增强体内，一个xUBF二聚体形成一个低密度蛋白质核心，DNA可能通过同相弯曲环绕在该核心周围形成一个单一的180碱基对的环。增强体结构提示了一种xUBF依赖的TATA盒结合蛋白复合体募集机制，而这两个因子之间没有直接相互作用。
