In eukaryotes, genes tend to be transcribed individually, and each gene is controlled by its own regulatory sequences. Regulatory sequences where activators bind are commonly found upstream from the promoter, but they can also be found downstream or even within introns in eukaryotes.
- 1 Where do activators and repressors bind?
- 2 Where would an activator bind on this operon?
- 3 How do eukaryotic activator proteins enhance transcription?
- 4 What do activator proteins bind to?
- 5 What are the two most important functional domains of a eukaryotic transcriptional activator protein?
- 6 Do activators bind to operator?
- 7 What is the difference between a repressor protein and an activator protein?
- 8 Do repressors bind to enhancers?
- 9 Is lactose an activator?
- 10 Is cAMP an activator?
- 11 What is the difference between an inducer and an activator?
- 12 Who is activator?
- 13 Which proteins are marked for destruction?
- 14 What is the function of the repressor protein?
Where do activators and repressors bind?
DNA segments near the promoter serve as protein-binding sites—most of these sites are termed operators—for regulatory proteins called activators and repressors. For some genes, the binding of an activator protein to its target DNA site is a necessary prerequisite for transcription to begin.
Where would an activator bind on this operon?
How do eukaryotic activator proteins enhance transcription?
Therefore activator proteins might also stimulate transcription by altering chromatin structure so as to make the promoter accessi- ble to RNA polymerase II and its associated factors.
What do activator proteins bind to?
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.
What are the two most important functional domains of a eukaryotic transcriptional activator protein?
Like activators, many eukaryotic repressors have two functional domains: a DNA-binding domain and a repression domain.
Do activators bind to operator?
In general, activators bind to the promoter site, while repressors bind to operator regions. Repressors prevent transcription of a gene in response to an external stimulus, whereas activators increase the transcription of a gene in response to an external stimulus.
What is the difference between a repressor protein and an activator protein?
A regulator protein that turns genes ON when it binds DNA is called an “activator protein,” and a regulator protein that turns genes OFF when it binds DNA is a “repressor protein.” … The ligand in a repressible system is called a “co-repressor.”29 mai 2013
Do repressors bind to enhancers?
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.
Is lactose an activator?
Catabolite activator protein (CAP) When lactose is present, the lac repressor loses its DNA-binding ability. This clears the way for RNA polymerase to bind to the promoter and transcribe the lac operon.
Is cAMP an activator?
In an environment with a low glucose concentration, cAMP accumulates and binds to the allosteric site on CRP (cAMP receptor protein), a transcription activator protein.
What is the difference between an inducer and an activator?
In molecular biology, an inducer is a molecule that regulates gene expression. … Activators generally bind poorly to activator DNA sequences unless an inducer is present. Activator binds to an inducer and the complex binds to the activation sequence and activates target gene. Removing the inducer stops transcription.
Who is activator?
Activator may refer to: Activator (genetics), a DNA-binding protein that regulates one or more genes by increasing the rate of transcription. Activator (phosphor), a type of dopant used in phosphors and scintillators. Enzyme activator, a type of effector that increases the rate of enzyme mediated reactions.
Which proteins are marked for destruction?
A doomed protein gets tagged with a chain of a protein called ubiquitin, which is like a molecular sign that reads, “destroy me.” The ubiquitin-tagged protein gets sent to the cell’s proteasome – the cell’s trash compactor – which breaks the protein into component amino acids.5 mar. 2014
What is the function of the repressor protein?
A repressor is a protein that turns off the expression of one or more genes. The repressor protein works by binding to the gene’s promoter region, preventing the production of messenger RNA (mRNA).