Do transcription factors bind to promoter or operator?

Transcription factors are a very diverse family of proteins and generally function in multi-subunit protein complexes. They may bind directly to special “promoter” regions of DNA, which lie upstream of the coding region in a gene, or directly to the RNA polymerase molecule.

What is the relationship between the promoter enhancers and transcription factors?

Explain the relationship between the promoter, enhancers, and transcription factors. Within this DNA sequence, proteins known as transcription factors bind to the enhancer and increase the activity of the promoter. Transcription factors increase chances of RNA being transcribed.

What binds to enhancers and promotes transcription?

The Promoter and the Transcription Machinery

An enhancer is a DNA sequence that promotes transcription. … The promoter region is immediately upstream of the coding sequence. The purpose of the promoter is to bind transcription factors that control the initiation of transcription.

What is enhancer in transcription?

Enhancers are short regulatory elements of accessible DNA that help establish the transcriptional program of cells by increasing transcription of target genes. They are bound by transcription factors, co-regulators, and RNA polymerase II (RNAP II).

Do activators bind to enhancers?

Most activators are DNA-binding proteins that bind to enhancers or promoter-proximal elements. The DNA site bound by the activator is referred to as an “activator-binding site”.

Is enhancer a promoter?

An enhancer is a sequence of DNA that functions to enhance transcription. A promoter is a sequence of DNA that initiates the process of transcription. A promoter has to be close to the gene that is being transcribed while an enhancer does not need to be close to the gene of interest.

Can a repressor bind to an enhancer?

Transcriptional repressors can bind to promoter or enhancer regions and block transcription. Like the transcriptional activators, repressors respond to external stimuli to prevent the binding of activating transcription factors.

Are activators transcription factors?

Transcription factors that are activators boost a gene’s transcription. Repressors decrease transcription. Groups of transcription factor binding sites called enhancers and silencers can turn a gene on/off in specific parts of the body.

How do enhancers and promoters differ quizlet?

A promoter is a DNA sequence near the transcription start site, which is bound by RNA polymerase during transcription initiation. Enhancers are DNA sequences that are farther away from the start site, they bind transcription factors and stimulate transcription above basal levels.

Are enhancers and silencers transcription factors?

Transcription factors are proteins that help turn specific genes “on” or “off” by binding to nearby DNA. Transcription factors that are activators boost a gene’s transcription. … Groups of transcription factor binding sites called enhancers and silencers can turn a gene on/off in specific parts of the body.

Why are enhancers not part of transcription of bacterial genes?

Speculate about why enhancers are not part of transcription of bacterial genes. … Bacteria mostly regulate gene expression at the level of translation, making transcription enhancers unnecessary. There is little to no intergenic space on bacterial chromosomes, which makes long-range-acting enhancer sequences unnecessary.

How does a transcription initiation complex control gene transcription?

Some transcription factors bind to a DNA promoter sequence near the transcription start site and help form the transcription initiation complex. Other transcription factors bind to regulatory sequences, such as enhancer sequences, and can either stimulate or repress transcription of the related gene.

Which of the following is a promoter region in prokaryotes closest to the transcription site?

Pribnow box
In prokaryotes, the promoter consists of two short sequences at -10 and -35 positions upstream from the transcription start site. The sequence at -10 is called the Pribnow box, or the -10 element, and usually consists of the six nucleotides TATAAT.

Is the TATA box an enhancer?

These studies revealed transcriptional enhancers that are specific for promoters that contain either DPE or TATA box elements. Thus, the core promoter not only mediates the initiation of transcription, but also functions as a regulatory element.

Do all transcription factors bind to DNA?

Due to the nature of these chemical interactions, most transcription factors bind DNA in a sequence specific manner. However, not all bases in the transcription factor-binding site may actually interact with the transcription factor. In addition, some of these interactions may be weaker than others.

What is the role of general transcription factors and where do they bind How do activators and repressors affect transcription?

GTF’s bind to the promoter region of the gene. How do activators and repressors affect transcription? They regulate transcription. Activators increase transcription and repressors decrease it.

Where do most transcription regulators bind?

How or where do most transcription regulators bind? Most transcriptional regulator proteins bind DNA as dimers. Dimerization roughly doubles the area of contact with the DNA, making the interaction tighter and more specific.

Can enhancers repress transcription?

Enhancers work as cis-regulatory elements to mediate both spatial and temporal control of development by turning on transcription in specific cells and/or repressing it in other cells.

Can transcription factors bind to more than one gene?

Attribution of transcription factor binding to regulation of an associated gene is an ongoing question. … One transcription factor can have multiple target genes. And, multiple transcription factors can regulate a single downstream gene’s expression.

Why do transcription factors bind to major groove?

Certain proteins bind to DNA to alter its structure or to regulate transcription (copying DNA to RNA) or replication (copying DNA to DNA). It is easier for these DNA binding proteins to interact with the bases (the internal parts of the DNA molecule) on the major groove side because the backbones are not in the way.

Which of these directly binds to the promoter?

Which of these directly bind(s) to the promoter? Both RNA polymerase and transcription factors bind with the promoter.