Question

What is meant by basal level transcription?

Answer 1

Very good question.

In cells, some genes are constitutively transcribed. These genes are typically under damped feed forward and positive control mechanisms and their protein products code for basic metabolic machinery and other proteins necessary for cell life. If they weren't there, the cell would die; therefore, it is careful to always transcribe enough new mRNAs to replace those being degraded.

In cases when more of these products are needed - for example, when a cell faces a metabolic challenge - then transcription is upregulated from this basic or basal level. The cell meets its need; negative feedback at higher transcript concentrations or copy number reduces transcription of the gene or genes involved in the response, and their rate of transcription goes back to the basic level.

For a superb example, read up on hypoxia inducible factor and the cassette of genes it regulates.

Answer 2

sometimes called a sequence-specific DNA-binding factor is a protein that binds to specific DNA sequences, thereby controlling the flow (or transcription) of genetic information from DNA to mRNA. Transcription factors perform this function alone or with other proteins in a complex, by promoting (as an activator), or blocking (as a repressor) the recruitment of RNA polymerase (the enzyme that performs the transcription of genetic information from DNA to RNA) to specific genes.
A defining feature of transcription factors is that they contain one or more DNA-binding domains (DBDs), which attach to specific sequences of DNA adjacent to the genes that they regulate.Additional proteins such as coactivators, chromatin remodelers, histone acetylases, deacetylases, kinases, and methylases, while also playing crucial roles in gene regulation, lack DNA-binding domains, and, therefore, are not classified as transcription factors.

Answer 3

i hope it will help u

Answer 4

In eukaryotes, an important class of transcription factors called general transcription factors (GTFs) are necessary for transcription to occur.many of these GTFs don't actually bind DNA but are part of the large transcription preinitiation complex that interacts with RNA polymerase directly. The most common GTFs are TFIIA, TFIIB, TFIID (see also TATA binding protein), TFIIE, TFIIF, and TFIIH. The preinitiation complex binds to promoter regions of DNA upstream to the gene that they regulate.

Answer 5

Thanks for providing such detailed answers!

Answer 6

Actually, this is a slight overloading of the basal transcriptional terminology.

The term "basal transcriptional level" should be differentiated from "basal transcriptional machinery." The former refers to the rate at which genes are transcribed. As well noted, @Ruchi. the basal transcriptional *machinery* refers to the non-specific sequence specific proteins necessary for transcription to occur.

Best wishes, all.