1TFB

NMR STUDIES OF HUMAN GENERAL TRANSCRIPTION FACTOR TFIIB: DYNAMICS AND INTERACTION WITH VP16 ACTIVATION DOMAIN, 20 STRUCTURES

Summary for 1TFB

• Entry DOI: 10.2210/pdb1tfb/pdb
• Descriptor: TFIIB (1 entity in total)
• Functional Keywords: transcription factor, human general transcription factor tfiib, c-terminal core domain, cyclin box fold
• Biological source: Homo sapiens (human)
• Cellular location: Nucleus: Q00403
• Total number of polymer chains: 1
• Total formula weight: 23198.11

Authors

Bagby, S.,Ikura, M. (deposition date: 1996-11-14, release date: 1997-03-12, Last modification date: 2024-05-22)

Primary citation

Hayashi, F.,Ishima, R.,Liu, D.,Tong, K.I.,Kim, S.,Reinberg, D.,Bagby, S.,Ikura, M.
Human general transcription factor TFIIB: conformational variability and interaction with VP16 activation domain.
Biochemistry, 37:7941-7951, 1998

PubMed Abstract: Human TFIIB, an essential factor in transcription of protein-coding genes by RNA polymerase II, consists of an amino-terminal zinc binding domain (TFIIBn) connected by a linker of about 60 residues to a carboxy-terminal core domain (TFIIBc). The TFIIB core domain has two internally repeated motifs, each comprising five alpha-helices arranged as in the cyclin box. Compared to the crystal structure of TFIIBc in complex with TBP and a TATA-containing oligonucleotide, the NMR-derived solution structure of free TFIIBc is more compact, with a different repeat-repeat orientation and a significantly shorter first helix in the second repeat. Analysis of backbone 15N relaxation parameters indicates the presence of relatively large amplitude, nanosecond time-scale motions in the TFIIBc interrepeat linker and structural fluctuations throughout the backbone. Interaction of TFIIBc with the acidic activation domain of VP16 or with TFIIBn induces 1H-15N chemical shift and line width changes concentrated in the first repeat, interrepeat linker and the first helix of the second repeat. These results suggest that TFIIB is somewhat pliable and that the conformation of the C-terminal core domain can be modulated by interaction with the N-terminal zinc binding domain. Furthermore, binding of the VP16 activation domain may promote TFIIBc conformations primed for binding to a TBP-DNA complex.

PubMed: 9609687
DOI: 10.1021/bi9801098

Experimental method

SOLUTION NMR