scholarly journals RNA Polymerase II Subunits 2, 3, and 11 Form a Core Subassembly with DNA Binding Activity

1997 ◽  
Vol 272 (41) ◽  
pp. 25851-25855 ◽  
Author(s):  
Makoto Kimura ◽  
Akira Ishiguro ◽  
Akira Ishihama
2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Shu-Hao Liou ◽  
Sameer K. Singh ◽  
Robert H. Singer ◽  
Robert A. Coleman ◽  
Wei-Li Liu

AbstractThe tumor suppressor p53 protein activates expression of a vast gene network in response to stress stimuli for cellular integrity. The molecular mechanism underlying how p53 targets RNA polymerase II (Pol II) to regulate transcription remains unclear. To elucidate the p53/Pol II interaction, we have determined a 4.6 Å resolution structure of the human p53/Pol II assembly via single particle cryo-electron microscopy. Our structure reveals that p53’s DNA binding domain targets the upstream DNA binding site within Pol II. This association introduces conformational changes of the Pol II clamp into a further-closed state. A cavity was identified between p53 and Pol II that could possibly host DNA. The transactivation domain of p53 binds the surface of Pol II’s jaw that contacts downstream DNA. These findings suggest that p53’s functional domains directly regulate DNA binding activity of Pol II to mediate transcription, thereby providing insights into p53-regulated gene expression.


1986 ◽  
Vol 6 (12) ◽  
pp. 4723-4733
Author(s):  
L A Chodosh ◽  
R W Carthew ◽  
P A Sharp

A simple approach has been developed for the unambiguous identification and purification of sequence-specific DNA-binding proteins solely on the basis of their ability to bind selectively to their target sequences. Four independent methods were used to identify the promoter-specific RNA polymerase II transcription factor MLTF as a 46-kilodalton (kDa) polypeptide. First, a 46-kDa protein was specifically cross-linked by UV irradiation to a body-labeled DNA fragment containing the MLTF binding site. Second, MLTF sedimented through glycerol gradients at a rate corresponding to a protein of native molecular weight 45,000 to 50,000. Third, a 46-kDa protein was specifically retained on a biotin-streptavidin matrix only when the DNA fragment coupled to the matrix contained the MLTF binding site. Finally, proteins from the most highly purified fraction which were eluted and renatured from the 44- to 48-kDa region of a sodium dodecyl sulfate-polyacrylamide gel exhibited both binding and transcription-stimulatory activities. The DNA-binding activity was purified 100,000-fold by chromatography through three conventional columns plus a DNA affinity column. Purified MLTF was characterized with respect to the kinetic and thermodynamic properties of DNA binding. These parameters indicate a high degree of occupancy of MLTF binding sites in vivo.


1996 ◽  
Vol 16 (9) ◽  
pp. 4639-4647 ◽  
Author(s):  
S J McBryant ◽  
E Meier ◽  
A Leresche ◽  
S J Sharp ◽  
V J Wolf ◽  
...  

The RNA polymerase III transcription initiation factor TFIIIB contains the TATA-box-binding protein (TBP) and polymerase III-specific TBP-associated factors (TAFs). Previous studies have shown that DNA oligonucleotides containing the consensus TATA-box sequence inhibit polymerase III transcription, implying that the DNA binding domain of TBP is exposed in TFIIIB. We have investigated the TATA-box DNA binding activity of Xenopus TFIIIB, using transcription inhibition assays and a gel mobility shift assay. Gel shift competition assays with mutant and nonspecific DNAs demonstrate the specificity of the TFIIIB-TATA box DNA complex. The apparent dissociation constant for this protein-DNA interaction is approximately 0.4 nM, similar to the affinity of yeast TBP for the same sequence. TFIIIB transcriptional activity and TATA-box binding activity cofractionate during a series of four ion-exchange chromatographic steps, and reconstituted transcription reactions demonstrate that the TATA-box DNA-protein complex contains TFIIIB TAF activity. Polypeptides with apparent molecular masses of 75 and 92 kDa are associated with TBP in this complex. These polypeptides were renatured after elution from sodium dodecyl sulfate-gels and tested individually and in combination for TFIIIB TAF activity. Recombinant TBP along with protein fractions containing the 75- and 92-kDa polypeptides were sufficient to reconstitute TFIIIB transcriptional activity and DNA binding activity, suggesting that Xenopus TFIIIB is composed of TBP along with these polypeptides.


2002 ◽  
Vol 22 (6) ◽  
pp. 1723-1733 ◽  
Author(s):  
Jennifer A. Ehley ◽  
Christian Melander ◽  
David Herman ◽  
Eldon E. Baird ◽  
Heather A. Ferguson ◽  
...  

ABSTRACT When targeted to sequences adjacent to a TATA element, pyrrole-imidazole (Py-Im) polyamides inhibit the DNA binding activity of TATA box binding protein (TBP) and basal transcription by RNA polymerase II. In the present study, we scanned the human immunodeficiency virus type 1 promoter for polyamide inhibition of TBP binding and transcription using a series of DNA constructs in which a polyamide binding site was placed at various distances from the TATA box. Polyamide interference with either TBP-DNA or TFIID-TFIIA-DNA contacts both upstream and downstream of the TATA element resulted in inhibition of transcription. Our results define important protein-DNA interactions outside of the TATA element and suggest that transcription inhibition of selected gene promoters can be achieved with polyamides that target unique sequences within these promoters at a distance from the TATA element. Our studies also demonstrate the utility of the Py-Im polyamides for discovery of functionally important protein-DNA contacts involved in transcription.


1986 ◽  
Vol 6 (12) ◽  
pp. 4723-4733 ◽  
Author(s):  
L A Chodosh ◽  
R W Carthew ◽  
P A Sharp

A simple approach has been developed for the unambiguous identification and purification of sequence-specific DNA-binding proteins solely on the basis of their ability to bind selectively to their target sequences. Four independent methods were used to identify the promoter-specific RNA polymerase II transcription factor MLTF as a 46-kilodalton (kDa) polypeptide. First, a 46-kDa protein was specifically cross-linked by UV irradiation to a body-labeled DNA fragment containing the MLTF binding site. Second, MLTF sedimented through glycerol gradients at a rate corresponding to a protein of native molecular weight 45,000 to 50,000. Third, a 46-kDa protein was specifically retained on a biotin-streptavidin matrix only when the DNA fragment coupled to the matrix contained the MLTF binding site. Finally, proteins from the most highly purified fraction which were eluted and renatured from the 44- to 48-kDa region of a sodium dodecyl sulfate-polyacrylamide gel exhibited both binding and transcription-stimulatory activities. The DNA-binding activity was purified 100,000-fold by chromatography through three conventional columns plus a DNA affinity column. Purified MLTF was characterized with respect to the kinetic and thermodynamic properties of DNA binding. These parameters indicate a high degree of occupancy of MLTF binding sites in vivo.


1999 ◽  
Vol 181 (14) ◽  
pp. 4299-4307 ◽  
Author(s):  
Nada Bsat ◽  
John D. Helmann

ABSTRACT Bacillus subtilis contains three metalloregulatory proteins belonging to the ferric uptake repressor (Fur) family: Fur, Zur, and PerR. We have overproduced and purified Fur protein and analyzed its interaction with the operator region controlling the expression of the dihydroxybenzoate siderophore biosynthesis (dhb) operon. The purified protein binds with high affinity and selectivity to the dhb regulatory region. DNA binding does not require added iron, nor is binding reduced by dialysis of Fur against EDTA or treatment with Chelex. Fur selectively inhibits transcription from the dhb promoter by ςA RNA polymerase, even if Fur is added after RNA polymerase holoenzyme. Since neither DNA binding nor inhibition of transcription requires the addition of ferrous ion in vitro, the mechanism by which iron regulates Fur function in vivo is not obvious. Mutagenesis of the furgene reveals that in vivo repression of the dhb operon by iron requires His97, a residue thought to be involved in iron sensing in other Fur homologs. Moreover, we identify His96 as a second likely iron ligand, since a His96Ala mutant mediates repression at 50 μM but not at 5 μM iron. Our data lead us to suggest that Fur is able to bind DNA independently of bound iron and that the in vivo role of iron is to counteract the effect of an inhibitory factor, perhaps another metal ion, that antagonizes this DNA-binding activity.


2001 ◽  
Vol 21 (21) ◽  
pp. 7523-7534 ◽  
Author(s):  
Lloyd A. Pereira ◽  
Jan A. van der Knaap ◽  
Vincent van den Boom ◽  
Fiona A. J. van den Heuvel ◽  
H. T. Marc Timmers

ABSTRACT The human RNA polymerase II transcription factor B-TFIID consists of TATA-binding protein (TBP) and the TBP-associated factor (TAF) TAFII170 and can rapidly redistribute over promoter DNA. Here we report the identification of human TBP-binding regions in human TAFII170. We have defined the TBP interaction domain of TAFII170 within three amino-terminal regions: residues 2 to 137, 290 to 381, and 380 to 460. Each region contains a pair of Huntington-elongation-A subunit-Tor repeats and exhibits species-specific interactions with TBP family members. Remarkably, the altered-specificity TBP mutant (TBPAS) containing a triple mutation in the concave surface is defective for binding the TAFII170 amino-terminal region of residues 1 to 504. Furthermore, within this region the TAFII170 residues 290 to 381 can inhibit the interaction between DrosophilaTAFII230 (residues 2 to 81) and TBP through competition for the concave surface of TBP. Biochemical analyses of TBP binding to the TATA box indicated that TAFII170 region 290-381 inhibits TBP-DNA complex formation. Importantly, the TBPAS mutant is less sensitive to TAFII170 inhibition. Collectively, our results support a mechanism in which TAFII170 induces high-mobility DNA binding by TBP through reversible interactions with its concave DNA binding surface.


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