1c9b
From Proteopedia
CRYSTAL STRUCTURE OF A HUMAN TBP CORE DOMAIN-HUMAN TFIIB CORE DOMAIN COMPLEX BOUND TO AN EXTENDED, MODIFIED ADENOVIRAL MAJOR LATE PROMOTER (ADMLP)
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 PubMedTranscription 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 AlsoReferences
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