| Structural highlights
Disease
[TBP_HUMAN] Defects in TBP are the cause of spinocerebellar ataxia type 17 (SCA17) [MIM:607136]. Spinocerebellar ataxia is a clinically and genetically heterogeneous group of cerebellar disorders. Patients show progressive incoordination of gait and often poor coordination of hands, speech and eye movements, due to degeneration of the cerebellum with variable involvement of the brainstem and spinal cord. SCA17 is an autosomal dominant cerebellar ataxia (ADCA) characterized by widespread cerebral and cerebellar atrophy, dementia and extrapyramidal signs. The molecular defect in SCA17 is the expansion of a CAG repeat in the coding region of TBP. Longer expansions result in earlier onset and more severe clinical manifestations of the disease.[1] [2] [3]
Function
[TBP_HUMAN] General transcription factor that functions at the core of the DNA-binding multiprotein factor TFIID. Binding of TFIID to the TATA box is the initial transcriptional step of the pre-initiation complex (PIC), playing a role in the activation of eukaryotic genes transcribed by RNA polymerase II. Component of the transcription factor SL1/TIF-IB complex, which is involved in the assembly of the PIC (preinitiation complex) during RNA polymerase I-dependent transcription. The rate of PIC formation probably is primarily dependent on the rate of association of SL1 with the rDNA promoter. SL1 is involved in stabilization of nucleolar transcription factor 1/UBTF on rDNA.[4] [TF2B_HUMAN] General factor that plays a major role in the activation of eukaryotic genes transcribed by RNA polymerase II.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Transcription initiation requires the assembly of a preinitiation complex (PIC), which is nucleated through binding of the TATA-box binding protein (TBP) to the promoter. Biochemical studies have shown, however, that TBP recognizes the TATA-box in both orientations and, therefore, cannot account for the directionality of PIC assembly. Transcription factor IIB (TFIIB) is essential for transcription initiation from RNA polymerase II promoters. Recent functional studies have identified a specific 7 bp TFIIB recognition element (BRE) immediately upstream of the TATA-box. We present here the 2.65 A resolution crystal structure of a human TFIIBc-TBPc complex bound to an idealized and extended adenovirus major late promoter. This structure now reveals that human TFIIBc binds to the promoter asymmetrically through base-specific contacts in the major groove upstream and in the minor groove downstream of the TATA-box. Binding of TFIIBc is, therefore, synergistic with TBPc requiring the distortion of the TATA-box. Thus, the newly described TFIIBc-DNA interface is likely to be a key determinant for the unidirectional assembly of a functional PIC.
Structural basis of preinitiation complex assembly on human pol II promoters.,Tsai FT, Sigler PB EMBO J. 2000 Jan 4;19(1):25-36. PMID:10619841[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Zuhlke C, Hellenbroich Y, Dalski A, Kononowa N, Hagenah J, Vieregge P, Riess O, Klein C, Schwinger E. Different types of repeat expansion in the TATA-binding protein gene are associated with a new form of inherited ataxia. Eur J Hum Genet. 2001 Mar;9(3):160-4. PMID:11313753 doi:10.1038/sj.ejhg.5200617
- ↑ Nakamura K, Jeong SY, Uchihara T, Anno M, Nagashima K, Nagashima T, Ikeda S, Tsuji S, Kanazawa I. SCA17, a novel autosomal dominant cerebellar ataxia caused by an expanded polyglutamine in TATA-binding protein. Hum Mol Genet. 2001 Jul 1;10(14):1441-8. PMID:11448935
- ↑ Silveira I, Miranda C, Guimaraes L, Moreira MC, Alonso I, Mendonca P, Ferro A, Pinto-Basto J, Coelho J, Ferreirinha F, Poirier J, Parreira E, Vale J, Januario C, Barbot C, Tuna A, Barros J, Koide R, Tsuji S, Holmes SE, Margolis RL, Jardim L, Pandolfo M, Coutinho P, Sequeiros J. Trinucleotide repeats in 202 families with ataxia: a small expanded (CAG)n allele at the SCA17 locus. Arch Neurol. 2002 Apr;59(4):623-9. PMID:11939898
- ↑ Friedrich JK, Panov KI, Cabart P, Russell J, Zomerdijk JC. TBP-TAF complex SL1 directs RNA polymerase I pre-initiation complex formation and stabilizes upstream binding factor at the rDNA promoter. J Biol Chem. 2005 Aug 19;280(33):29551-8. Epub 2005 Jun 21. PMID:15970593 doi:10.1074/jbc.M501595200
- ↑ Tsai FT, Sigler PB. Structural basis of preinitiation complex assembly on human pol II promoters. EMBO J. 2000 Jan 4;19(1):25-36. PMID:10619841 doi:10.1093/emboj/19.1.25
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