Biomedical subjects

S Buratowski

Publications and source records attributed to S Buratowski.

45 records · Page 3Linked to original sources

PubMed1992

Transcription factor IID mutants defective for interaction with transcription factor IIA.

Transcription factor IID (TFIID) recognizes the TATA element of promoters transcribed by RNA polymerase II (RNAPII) and serves as the base for subsequent association by other general transcription factors and RNAPII. The carboxyl-terminal domain of TFIID is highly conserved and contains an imperfect repetition of a 60-amino acid sequence. These repeats are separated by a region rich in basic amino acids. Mutagenesis of the lysines in this region resulted in a conditioned phenotype in vivo, and the mutant proteins were defective for interactions with transcription factor IIA in vitro. Binding of TFIID to DNA was unaffected. These results suggest that the basic domain of TFIID is important for protein-protein interactions.

Amino Acid Sequence↗

PubMed1991

RNA polymerase II-associated proteins are required for a DNA conformation change in the transcription initiation complex.

Proteins purified on the basis of their affinity for RNA polymerase II effectively substitute for previously defined transcription initiation factors. In two assays, formation of initiation complexes and transcription in vitro, the RNA polymerase II-associated proteins behaved identically to a fraction containing transcription factors IIE and IIF. Both fractions greatly stabilized the association of polymerase with the promoter and were required for the formation of complete initiation complexes. By using the DNA-cleaving reagent phenanthroline.copper in footprinting reactions, the RNA polymerase II-associated proteins were shown to be required for a DNA conformation change near the initiation site of the promoter. Based on similarity to the prokaryotic transcription complex, this conformation change is likely to represent a transition from a closed to an open complex.

Cellulose↗

PubMed1990

Transcription initiation complexes and upstream activation with RNA polymerase II lacking the C-terminal domain of the largest subunit.

RNA polymerase II assembles with other factors on the adenovirus type 2 major late promoter to generate pairs of transcription initiation complexes resolvable by nondenaturing gel electrophoresis. The pairing of the complexes is caused by the presence or absence of the C-terminal domain of the largest subunit. This domain is not required for transcription stimulation by the major late transcription factor in vitro.

Amino Acid Sequence↗

PubMed1989

Isolation of the gene encoding the yeast TATA binding protein TFIID: a gene identical to the SPT15 suppressor of Ty element insertions.

We report the cloning of the gene that encodes the yeast TATA binding protein TFIID. TFIID contains 240 amino acids and has no obvious sequence similarity to other known proteins. TFIID was synthesized in vitro and in two separate assays behaved identically to the protein purified from yeast. TFIID bound to TATA elements from the adenovirus major late promoter (TATAAAA) and the yeast LEU2 promoter (TATTTAA) and formed protein-DNA complexes stable to electrophoresis only in the presence of TFIIA. In vitro-synthesized yeast TFIID also complemented a mammalian in vitro transcription system that lacked TFIID. Comparison of the yeast TFIID gene with the yeast SPT15 gene (suppressor of Ty element insertions) showed that the two genes are identical. This finding indicates that the yeast TFIID activity defined in vitro is responsible for specific transcription in vivo.

Amino Acid Sequence↗

PubMed1989

Five intermediate complexes in transcription initiation by RNA polymerase II.

A native gel electrophoresis DNA binding assay was used to resolve complexes formed on the adenovirus Major Late Promoter by general transcription factors and RNA polymerase II. Five sets of complexes containing distinct components were identified. These complexes were generated by sequential binding of TFIID, TFIIA, TFIIB, RNA polymerase II, and TFIIE. The relative positions of each of the factors in the complexes were determined by DNAase I footprint analysis. TFIIA, derived from yeast or mammalian cells, formed a complex with yeast TFIID and the TATA element. TFIIB bound to this complex and probably acts as a "bridge" to the polymerase and the initiation site. The addition of ATP or dATP, necessary for "activation" of transcription, resulted in an alteration of the footprint in the +20 to +30 region, the same area protected upon addition of TFIIE to the initiation complex. Addition of ribonucleotide triphosphates generated new complexes that contained accurately initiated transcripts associated with the transcription machinery and the template DNA. A model for the interactions of components in initiation of transcription by RNA polymerase II is proposed.

Adenoviridae↗

PubMed1989

Identification of a yeast protein homologous in function to the mammalian general transcription factor, TFIIA.

The yeast homolog of the mammalian RNA polymerase II general transcription factor TFIIA has been identified by complementation of a mammalian in vitro transcription system depleted for TFIIA. Like the mammalian factor, the yeast protein does not bind DNA, alters the size of the TFIID DNase I footprint at the adenovirus major late promoter, and forms specific TFIIA-TFIID-DNA complexes which are stable during electrophoresis in native acrylamide gels. The partially purified yeast factor was used to investigate its effect on the binding of TFIID to the major late promoter. Contrary to earlier models, we find that TFIIA does not significantly change the affinity or kinetics of TFIID binding, suggesting that it acts by altering the conformation of TFIID and/or by serving as a bridge between TFIID and the other general transcription factors.

Adenoviridae↗

PubMed1989

Yeast TATA-binding protein TFIID binds to TATA elements with both consensus and nonconsensus DNA sequences.

The DNA binding properties of the yeast TATA element-binding protein TFIID were investigated. The affinity (apparent equilibrium dissociation constant) of TFIID for the adenovirus major late promoter consensus TATA element is 2 x 10(-9) M, a value similar to the affinity of gene-specific regulatory proteins for their binding sites. TFIID binding is highly specific and recognizes nonspecific sites with approximately 10(5)-fold lower affinity. Despite this specificity, TFIID also binds with high affinity to several TATA elements that do not match the consensus TATA sequences (TATAAA and TATATA): the yeast LEU2 TATA (TATTATTTA), the simian virus 40 TATA (CTTATTTAT), and the yeast CYC1 -10 TATA (TTATACATT) all bound TFIID. Furthermore, TFIID was active in promoting transcription in vitro from the nonconsensus TATA elements. Thus, contrary to previous suggestions, the existence of nonconsensus TATA elements does not itself indicate the existence of multiple TATA-binding factors.

Base Sequence↗

PubMed1989

A yeast protein possesses the DNA-binding properties of the adenovirus major late transcription factor.

The adenovirus major late transcription factor (MLTF), or upstream stimulatory factor, is a human promoter-specific transcription factor which recognizes the near-palindromic sequence GGCCACGTGACC (R. W. Carthew, L. A. Chodosh, and P. A. Sharp, Cell 43:439-448, 1985; L. A. Chodosh, R. W. Carthew, and P. A. Sharp, Mol. Cell. Biol. 6:4723-4733, 1986; M. Sawadogo and R. G. Roeder, Cell 43:165-175, 1985). We describe here a protein found in the yeast Saccharomyces cerevisiae which possesses DNA-binding properties that are virtually identical to those of human MLTF. These two proteins recognize the same DNA-binding site, make the same purine nucleotide contacts, and are affected in the same manner by mutations in the MLTF-binding site.

Adenoviridae↗

PubMed1988

Function of a yeast TATA element-binding protein in a mammalian transcription system.

Saccharomyces cerevisiae contains a protein which is functionally similar to the mammalian TATA element-binding transcription factor, TFIID. The yeast factor substitutes for TFIID in a mammalian RNA polymerase II in vitro transcription system, forms a stable preinitiation complex on the Adenovirus-2 major late promoter, and binds specifically to the TATA boxes of the viral promoter and the yeast CYC1 promoter. Interestingly, the yeast factor promotes initiation at a distance from the TATA element typical of a mammalian system.

DNA-Binding Proteins↗