Where are transcription factor binding sites?
Transcription Factor Binding Sites (TFBSs) Transcription factors (TFs) are proteins with DNA binding activity that are involved in the regulation of transcription. Generally, TFs modulate gene expression by binding to gene promoter regions or to distal regions called enhancers.
Where do the transcription factors bind to eukaryotic DNA?
Eukaryotic transcription is carried out in the nucleus of the cell and proceeds in three sequential stages: initiation, elongation, and termination. Eukaryotes require transcription factors to first bind to the promoter region and then help recruit the appropriate polymerase.
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.
Why do transcription factors bind to DNA?
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.
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.
How do transcription factors bind to promoters?
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.
Where do activator proteins bind?
Activator proteins bind to regulatory sites on DNA nearby to promoter regions that act as on/off switches. This binding facilitates RNA polymerase activity and transcription of nearby genes.
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.
Would the relative position where a transcription factor or an activator repressor binds DNA be the same across different individuals?
the answer is yes; humans only differ in a very small percentage of their genome and the gene structure and sequence is mostly the same across different individuals. Oct1 is a transcription factor that regulates the expression of lactase; it is an activator.
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 does the lac operon bind?
The promoter of the lac operon has two binding sites. One site is the location where RNA polymerase binds. The second location is the binding site for a complex between the catabolite activator protein (CAP) and cyclic AMP (cAMP).
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”. … The activity of activators can be regulated.
What is the name of DNA control sequence to which transcription activators and repressors bind?
Enhancers: An enhancer is a DNA sequence that promotes transcription. Each enhancer is made up of short DNA sequences called distal control elements. Activators bound to the distal control elements interact with mediator proteins and transcription factors.
How does Oct1 recognize the position on the DNA molecule where it should bind?
For Oct1, distance does not matter. Once bound to DNA, the DNA bends to bring Oct1 and the gene together. How does Oct1 recognize the position on the DNA molecule where it should bind? Transcription factors recognize the binding site based on the specific sequence of the enhancer/binding site/promoter.
How do transcription factors work what is their relationship to control regions in DNA?
Transcription factors are proteins possessing domains that bind to the DNA of promoter or enhancer regions of specific genes. They also possess a domain that interacts with RNA polymerase II or other transcription factors and consequently regulates the amount of messenger RNA (mRNA) produced by the gene.
When a repressor binds to the operator site on DNA?
In molecular genetics, a repressor is a DNA- or RNA-binding protein that inhibits the expression of one or more genes by binding to the operator or associated silencers. A DNA-binding repressor blocks the attachment of RNA polymerase to the promoter, thus preventing transcription of the genes into messenger RNA.
How do eukaryotic transcription factors exert their effects on transcription when their binding sites can be thousands of base pairs away from the promoter?
how do eukaryotic transcription factors exert their effects on transcription when their binding sites can be thousands of base pairs away from the promoter? … this large and complex general transcription factor has a DNA helicase activity that exposes the template for RNA polymerase II transcription.
How do transcription factors inhibit transcription?
Transcription factors (TFs) are regulatory proteins whose function is to activate (or more rarely, to inhibit) transcription of DNA by binding to specific DNA sequences. TFs have defined DNA-binding domains with up to 106-fold higher affinity for their target sequences than for the remainder of the DNA strand.
How do transcription factors find their targets?
Transcription factors (which are described in the video) have to be able to first scan the genome so they can find their target sites and then bind there, which will turn genes on or off. It’s known that they can also randomly attach to the genome non-specifically.
When a transcription regulator binds to DNA its most important interactions occur with which of the following?
When a transcription regulator binds to DNA, its most important interactions occur with: nucleotide pairs in the major groove of the double helix.
Where does transcription take place where does translation take place?
Transcription occurs in the nucleus in eukaryotic organisms, while translation occurs in the cytoplasm and endoplasmic reticulum. Both processes occur in the cytoplasm in prokaryotes. The factor controlling these processes is RNA polymerase in transcription and ribosomes in translation.
What will result from the binding of a transcription factor to an enhancer region?
Increased transcription of a distant gene will result from the binding of a transcription factor to an enhancer region. … If too much of an activating transcription factor were present, then transcription would be increased in the cell. This could lead to dramatic alterations in cell function.
Where do transcription regulators usually bind on DNA double helix?
Transcription regulators usually bind where on a DNA double helix? nucleotide pairs in the major groove of the double helix.
Which of the following events occur when TATA binding protein binds to the DNA?
When the TATA-binding protein binds to the TATA sequence in DNA, the protein causes the DNA helix to bend. The kink that occurs is thought to signal assembly of the transcriptional complex and initiation of transcription. … Binding leads to assembly of the rest of the transcription complex at the initiation site.
How are most eukaryotic transcription regulators able to affect transcription when their binding sites are far from the promoter?
How are most eukaryotic transcription regulators able to affect transcription when their binding sites are far from the promoter? By looping out the intervening DNA between their binding site and the promoter.