Structure of human upstream binding factor HMG box 5 and site for binding of the cell-cycle regulatory factor TAF1Rong, H., Li, Y., Shi, X., Zhang, X., Gao, Y., Dai, H., Teng, M.K., Niu, L.W., Liu, Q., Hao, Q.
(2007) Acta Crystallogr D Biol Crystallogr 63: 730-737
- PubMed: 17505112
- DOI: https://doi.org/10.1107/S0907444907017027
- Primary Citation of Related Structures:
- PubMed Abstract:
The fifth HMG-box domain in human upstream binding factor (hUBF) contributes to the synthesis of rRNA by RNA polymerase I (Pol I). The 2.0 A resolution crystal structure of this protein has been solved using the single-wavelength anomalous dispersion method (SAD). The crystal structure and the reported NMR structure have r.m.s. deviations of 2.18-3.03 A for the C(alpha) atoms. However, there are significant differences between the two structures, with displacements of up to 9.0 A. Compared with other HMG-box structures, the r.m.s. deviations for C(alpha) atoms between hUBF HMG box 5 and HMG domains from Drosophila melanogaster protein D and Rattus norvegicus HMG1 are 1.5 and 1.6 A, respectively. This indicates that the differences between the crystal and NMR structures of hUBF HMG box 5 are larger than those with its homologous structures. The differences between the two structures potentially reflect two states with different structures. The specific interactions between the hUBF HMG box 5 and the first bromodomain of TBP-associated factor 1 (TAF1) were studied by ultrasensitive differential scanning calorimetry and chemical shift perturbation. Based on these experimental data, possible sites in hUBF HMG box 5 that may interact with the first bromodomain of TAF1 were proposed.
Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.