DNA Sequence-Specific Recognition by theSaccharomyces cerevisiae“TATA” Binding Protein:  Promoter-Dependent Differences in the Thermodynamics and Kinetics of Binding†

Biochemistry ◽  
1998 ◽  
Vol 37 (45) ◽  
pp. 15842-15849 ◽  
Author(s):  
Victoria Petri ◽  
Mark Hsieh ◽  
Elizabeth Jamison ◽  
Michael Brenowitz
2001 ◽  
Vol 276 (18) ◽  
pp. 14623-14627 ◽  
Author(s):  
Jiong Wu ◽  
Kay M. Parkhurst ◽  
Robyn M. Powell ◽  
Lawrence J. Parkhurst

1993 ◽  
Vol 13 (7) ◽  
pp. 3841-3849
Author(s):  
B Zenzie-Gregory ◽  
A Khachi ◽  
I P Garraway ◽  
S T Smale

Promoters containing Sp1 binding sites and an initiator element but lacking a TATA box direct high levels of accurate transcription initiation by using a mechanism that requires the TATA-binding protein (TBP). We have begun to address the role of TBP during transcription from Sp1-initiator promoters by varying the nucleotide sequence between -14 and -33 relative to the start site. With each of several promoters containing different upstream sequences, we detected accurate transcription both in vitro and in vivo, but the promoter strengths varied widely, particularly with the in vitro assay. The variable promoter activities correlated with, but were not proportional to, the abilities of the upstream sequences to function as TATA boxes, as assessed by multiple criteria. These results confirm that accurate transcription can proceed in the presence of an initiator, regardless of the sequence present in the -30 region. However, the results reveal a role for this upstream region, most consistent with a model in which initiator-mediated transcription requires binding of TBP to the upstream DNA in the absence of a specific recognition sequence. Moreover, in vivo it appears that the promoter strength is modulated less severely by altering the -30 sequence, consistent with a previous suggestion that TBP is not rate limiting in vivo for TATA-less promoters. Taken together, these results suggest that variations in the structure of a core promoter might alter the rate-limiting step for transcription initiation and thereby alter the potential modes of transcriptional regulation, without severely changing the pathway used to assemble a functional preinitiation complex.


1993 ◽  
Vol 13 (7) ◽  
pp. 3841-3849 ◽  
Author(s):  
B Zenzie-Gregory ◽  
A Khachi ◽  
I P Garraway ◽  
S T Smale

Promoters containing Sp1 binding sites and an initiator element but lacking a TATA box direct high levels of accurate transcription initiation by using a mechanism that requires the TATA-binding protein (TBP). We have begun to address the role of TBP during transcription from Sp1-initiator promoters by varying the nucleotide sequence between -14 and -33 relative to the start site. With each of several promoters containing different upstream sequences, we detected accurate transcription both in vitro and in vivo, but the promoter strengths varied widely, particularly with the in vitro assay. The variable promoter activities correlated with, but were not proportional to, the abilities of the upstream sequences to function as TATA boxes, as assessed by multiple criteria. These results confirm that accurate transcription can proceed in the presence of an initiator, regardless of the sequence present in the -30 region. However, the results reveal a role for this upstream region, most consistent with a model in which initiator-mediated transcription requires binding of TBP to the upstream DNA in the absence of a specific recognition sequence. Moreover, in vivo it appears that the promoter strength is modulated less severely by altering the -30 sequence, consistent with a previous suggestion that TBP is not rate limiting in vivo for TATA-less promoters. Taken together, these results suggest that variations in the structure of a core promoter might alter the rate-limiting step for transcription initiation and thereby alter the potential modes of transcriptional regulation, without severely changing the pathway used to assemble a functional preinitiation complex.


2018 ◽  
Vol 22 (1) ◽  
pp. 145-152 ◽  
Author(s):  
E. B. Sharypova ◽  
I. A. Drachkova ◽  
E. V. Kashina ◽  
D. A. Rasskazov ◽  
P. M. Ponomarenko ◽  
...  

Author(s):  
R. J. Lauf

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.


2004 ◽  
Vol 29 (2) ◽  
pp. 1-9
Author(s):  
Mustapha Boulghallat ◽  
Ahmed Jouaiti ◽  
Norbert Gérard

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