title: Structure of human upstream binding factor HMG box 5 and site for binding of the cell-cycle regulatory factor TAF1.
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.
authors.affiliation: 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.
authors.forename: Hui
authors.initials: H
authors.lastname: Rong
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Shi
authors.forename: Xiao
authors.initials: X
authors.lastname: Zhang
authors.forename: Yongxiang
authors.initials: Y
authors.lastname: Gao
authors.forename: Haiming
authors.initials: H
authors.lastname: Dai
authors.forename: Maikun
authors.initials: M
authors.lastname: Teng
authors.forename: Liwen
authors.initials: L
authors.lastname: Niu
authors.forename: Qun
authors.initials: Q
authors.lastname: Liu
authors.forename: Quan
authors.initials: Q
authors.lastname: Hao
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D017931:DNA Primers / Q000235:genetics; D029721:Drosophila Proteins / Q000737:chemistry; D024002:HMGB Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D051548:Histone Acetyltransferases; D006801:Humans; D066298:In Vitro Techniques; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D035463:Pol1 Transcription Initiation Complex Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D035381:TATA-Binding Protein Associated Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D013816:Thermodynamics; D035362:Transcription Factor TFIID / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D029721:Drosophila Proteins; D024002:HMGB Proteins; D035463:Pol1 Transcription Initiation Complex Proteins; D011994:Recombinant Proteins; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; C063844:transcription factor UBF; D051548:Histone Acetyltransferases; C069001:TATA-binding protein associated factor 250 kDa