1nvp
From Proteopedia
HUMAN TFIIA/TBP/DNA COMPLEX
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[T2AG_HUMAN] TFIIA is a component of the transcription machinery of RNA polymerase II and plays an important role in transcriptional activation. TFIIA in a complex with TBP mediates transcriptional activity.[4] [TF2AA_HUMAN] TFIIA is a component of the transcription machinery of RNA polymerase II and plays an important role in transcriptional activation. TFIIA in a complex with TBP mediates transcriptional activity.[5] [6] [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.[7] 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 PubMedRNA polymerase II-dependent transcription requires the assembly of a multi-protein, preinitiation complex on core promoter elements. Transcription factor IID (TFIID) comprising the TATA box-binding protein (TBP) and TBP-associated factors (TAFs) is responsible for promoter recognition in this complex. Subsequent association of TFIIA and TFIIB provides enhanced complex stability. TFIIA is required for transcriptional stimulation by certain viral and cellular activators, and favors formation of the preinitiation complex in the presence of repressor NC2. The X-ray structures of human and yeast TBP/TFIIA/DNA complexes at 2.1A and 1.9A resolution, respectively, are presented here and seen to resemble each other closely. The interactions made by human TFIIA with TBP and DNA within and upstream of the TATA box, including those involving water molecules, are described and compared to the yeast structure. Of particular interest is a previously unobserved region of TFIIA that extends the binding interface with TBP in the yeast, but not in the human complex, and that further elucidates biochemical and genetic results. Novel interactions between the components of human and yeast TFIIA/TBP/DNA complexes.,Bleichenbacher M, Tan S, Richmond TJ J Mol Biol. 2003 Sep 26;332(4):783-93. PMID:12972251[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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