Question

Fill in the blank- During eukaryotic transcription, the assembly of the general transcription factors begins with the binding of the factor________in a complex with the general transcription factor_________to DNA, causing a marked local distortion in the double helix. This factor binds at the DNA sequence called the________box, which is typically located 25 nucleotides upstream from the transcription start site. Once RNA polymerase II has been brought to the promoter DNA, it must be released to begin making transcripts. This release process is facilitated by the addition of phosphate groups to the tail of RNA polymerase by the factor_______. General transcription factor and RNA polymerase are not sufficient to efficiently initiate transcription in the cell and are affected by proteins bound thousands of nucleotides away from the promoter. Proteins that link distantly bound transcription regulators to RNA polymerase and the general transcription factors include the large complex of proteins called the _________. The packaging of DNA into chromatin also affects transcriptional initiation, and histone________ is an enzyme that can render the DNA less accessible to the general transcription factors.

Answer 1

Transcription factor II D (TFIID) is a general transcription factor that helps regulate gene expression and is a part of the RNA polymerase II preinitiation complex in the eukaryotic transcription process. This TFIID is the one that first recognizes the TATA element, and TATA-binding protein (TBP) is a part of TFIID and is also a general transcription factor that binds to the TATA box DNA sequence usually present upstream of the initiator box sequence.
The Transcription Factor IIH is a transcription factor that allows helps in the separation of the double-stranded DNA into single strands by changing the position of the RNA polymerase II tail with respect to its body by phosphorylating its tail. When the carboxy-terminal domain of the RNA polymerase II is unphosphorylated, it binds to a multiprotein complex that receives signals from the upstream activator proteins while conveying these signals to the RNA polymerase II to attach to the promoter. This multiprotein complex is called the Mediator. From histones, Histone deacetylase (HDAC) removes the acetyl group, thus providing for the attachment of DNA to the histones (coiling of DNA around the histones), leading to less availability of DNA for gene expression.

Thus, the required answer is as follows:

During eukaryotic transcription, the assembly of the general transcription factors begins with the binding of the factor Transcription Factor II D (TFIID) in a complex with the general transcription factor TATA-binding protein (TBP) to DNA, causing a marked local distortion in the double helix. This factor binds at the DNA sequence called the TATA box, which is typically located 25 nucleotides upstream from the transcription start site. Once RNA polymerase II has been brought to the promoter DNA, it must be released to begin making transcripts. This release process is facilitated by the addition of phosphate groups to the tail of RNA polymerase by the factor Transcription Factor II H (TFIIH). General transcription factor and RNA polymerase are not sufficient to efficiently initiate transcription in the cell and are affected by proteins bound thousands of nucleotides away from the promoter. Proteins that link distantly bound transcription regulators to RNA polymerase and the general transcription factors include the large complex of proteins called the Mediator. The packaging of DNA into chromatin also affects transcriptional initiation, and histone deacetylase is an enzyme that can render the DNA less accessible to the general transcription factors.