Biology Department - Arik Dvir - Research

Dr. Dvir's Research: Molecular Mechanisms of Gene Transcription

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Protein Components of the Basal System for RNA Polymerase II Transcription

TOR1 RNA Polymerase II Rat This large, 12-subunit enzyme is the main ¡§engine¡¨ of the transcription process. It catalyzes DNA-dependent mRNA synthesis from ribonucleotide building blocks.

TOR2 TBP Yeast This 27 kDa polypeptide binds with high affinity to the TATA box region of the promoter, providing the most crucial protein-DNA interaction in the recruitment of the pre-initiation complex. The other general transcription factors subsequently enter the pre-initiation complex, relying on the presence of TBP. TBP is tightly associated with additional polypeptides in the nucleus, forming the so-called TFIID complex that is important in activated transcription. In basal transcription, however, TBP alone is sufficient to the formation of a fully functional transcription complex.

TOR3 TFIIB Human A single polypeptide of 35 kDa, this protein binds to the promoter-TBP complex, by forming direct protein-protein interactions with TBP, and to some extent, direct protein-DNA interactions with promoter DNA.

TOR4 TFIIE Human A heterodimer made of two polypeptide chains, 34 kDa and 56 kDa. TFIIE has a role in the initial melting of the promoter region and is essential to recruit TFIIH to the pre-initiation complex as well as to the early elongation complex.

TOR5 TFIIF Human This protein is a heterodimer consisting of two polypeptide chains: 30 kDa and 74 kDa. TFIIF binds to the TBP-TFIIB-promoter complex, and by its direct protein-protein interactions with the RNA polymerase II, recruits the polymerase to the pre-initiation complex. TFIIF has an additional function in the Elongation phase of transcription, in addition to its role in the formation of the pre-initiation complex.

TOR6 TFIIH Rat This a large, multifunctional transcription factor made of nine polypeptides. It has three intrinsic catalytic activities: (i) an ATP/GTP dependent protein kinase, (ii) an ATP-dependent 3' ->5' DNA helicase, and (iii) an ATP-dependent, 5' ->3' DNA helicase. In basal transcription, the DNA helicase subunits are crucial for open-complex formation, and for expansion of the transcription bubble during the Promoter Escape stage of early transcription.

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RNA Polymerase II	Rat	This large, 12-subunit enzyme is the main ¡§engine¡¨ of the transcription process. It catalyzes DNA-dependent mRNA synthesis from ribonucleotide building blocks.
TBP	Yeast	This 27 kDa polypeptide binds with high affinity to the TATA box region of the promoter, providing the most crucial protein-DNA interaction in the recruitment of the pre-initiation complex. The other general transcription factors subsequently enter the pre-initiation complex, relying on the presence of TBP. TBP is tightly associated with additional polypeptides in the nucleus, forming the so-called TFIID complex that is important in activated transcription. In basal transcription, however, TBP alone is sufficient to the formation of a fully functional transcription complex.
TFIIB	Human	A single polypeptide of 35 kDa, this protein binds to the promoter-TBP complex, by forming direct protein-protein interactions with TBP, and to some extent, direct protein-DNA interactions with promoter DNA.
TFIIE	Human	A heterodimer made of two polypeptide chains, 34 kDa and 56 kDa. TFIIE has a role in the initial melting of the promoter region and is essential to recruit TFIIH to the pre-initiation complex as well as to the early elongation complex.
TFIIF	Human	This protein is a heterodimer consisting of two polypeptide chains: 30 kDa and 74 kDa. TFIIF binds to the TBP-TFIIB-promoter complex, and by its direct protein-protein interactions with the RNA polymerase II, recruits the polymerase to the pre-initiation complex. TFIIF has an additional function in the Elongation phase of transcription, in addition to its role in the formation of the pre-initiation complex.
TFIIH	Rat	This a large, multifunctional transcription factor made of nine polypeptides. It has three intrinsic catalytic activities: (i) an ATP/GTP dependent protein kinase, (ii) an ATP-dependent 3' ->5' DNA helicase, and (iii) an ATP-dependent, 5' ->3' DNA helicase. In basal transcription, the DNA helicase subunits are crucial for open-complex formation, and for expansion of the transcription bubble during the Promoter Escape stage of early transcription.