Table of Contents
What are prokaryotic transcription factors?
Transcription factors (TFs) are proteins that bind to specific sequences on the DNA near their target genes, thus modulating transcription initiation. TFs can activate or repress transcription depending where they bind relative to the transcription start site of the target gene [1].
Are general transcription factors found in prokaryotes?
Eukaryotes form and initiation complex with the various transcription factors that dissociate after initiation is completed. There is no such structure seen in prokaryotes.
What organelle does transcription occur?
Answer and Explanation: The organelle that transcription takes place in is the nucleus in eukaryotes and the cytoplasm in prokaryotes.
What are general transcription factors made of?
The general transcription factors (GTF) include the TATAA box binding protein (TBP), a number of TBP-associated factors, and the RNA polymerase II enzyme, which synthesize mRNA strands from the genetic information.
What are general transcription factors and how do they function?
General transcription factors (GTFs), also known as basal transcriptional factors, are a class of protein transcription factors that bind to specific sites (promoter) on DNA to activate transcription of genetic information from DNA to messenger RNA.
What are the general transcription factors in eukaryotes?
The holoenzyme consists of a preformed complex of RNA polymerase II, the general transcription factors TFIIB, TFIIE, TFIIF, and TFIIH, and several other proteins that activate transcription.
Where are general transcription factors found?
the nucleus
Nuclear localization. In eukaryotes, transcription factors (like most proteins) are transcribed in the nucleus but are then translated in the cell’s cytoplasm. Many proteins that are active in the nucleus contain nuclear localization signals that direct them to the nucleus.
How does prokaryotic transcription differ from eukaryotic?
Main Difference – Prokaryotic vs. Eukaryotic Transcription. Prokaryotic transcription occurs in the cell cytoplasm and, in prokaryotes, both transcription and translation happen simultaneously. Eukaryotic transcription occurs in the cell nucleus and, in eukaryotes, transcription and translation differ in space and time …
What organelles are involved in translation and transcription?
Ribosome: a cellular organelle that is responsible for making proteins. RNA: an acid found in all living things that carries messages from DNA to the rest of the cell to be made into protein. A basic illustration of the processes of transcription and translation. Click for more detail.
Where does transcription occur in prokaryotic cells?
cytoplasm
The prokaryotes, which include bacteria and archaea, lack membrane-bound nuclei and other organelles, and transcription occurs in the cytoplasm of the cell.
Where do general transcription factors come from?
How many general transcription factors are there?
Five general transcription factors are required for initiation of transcription by RNA polymerase II in reconstituted in vitro systems (Figure 6.12). The promoters of many genes transcribed by polymerase II contain a sequence similar to TATAA 25 to 30 nucleotides upstream of the transcription start site.
What are general transcription factors in eukaryotes?
How is transcription controlled in prokaryotes?
There are two majors kinds of proteins that control prokaryotic transcription: repressors and activators. Repressors bind to an operator region to block the action of RNA polymerase. Activators bind to the promoter to enhance the binding of RNA polymerase.
Which organelle is responsible for translating proteins?
Ribosomes
Ribosomes are the organelles responsible for protein translation and are composed of ribosomal RNA (rRNA) and proteins. Some ribosomes are found in the cytoplasm, a gel-like substance that organelles float in and some are found in the rough endoplasmic reticulum.
Which of the following cell organelles is involved in the process of protein synthesis?
Ribosomes are the micro particles of ribonucleoprotein found in the cell, hence they are called RNP particles. These are the main sites of protein synthesis where synthesis of protein occurs. They are therefore called protein factory of the cell.
What are the five general transcription factors?
Expression of the human serum albumin gene is regulated by five transcription factors, four of which bind to the promoter region. TFII=transcription factor II, HNF1=Hepatocyte nuclear factor 1, NFY=nuclear factor Y, C/EBP=CCAAT/Enhancer binding protein, NF1=nuclear factor 1.
In prokaryotes, which lack membrane-bound nuclei and other organelles, transcription occurs in the cytoplasm of the cell. RNA Polymerase is the enzyme that produces the mRNA molecule (just like DNA polymerase produced a new DNA molecule during DNA replication). Prokaryotes use the same RNA polymerase to transcribe all of their genes.
What are the phases of transcription in prokaryotes?
In prokaryotic organisms transcription occurs in three phases known as initiation, elongation and termination. RNA is synthesized by a single RNA polymerase enzyme which contains multiple polypeptide subunits.
What are transcription factors?
An overview of prokaryotic transcription factors : a summary of function and occurrence in bacterial genomes Transcriptional initiation is arguably the most important control point for gene expression. It is regulated by a combination of factors, including DNA sequence and its three-dimensional topology, proteins and small molecules.
What is required for transcription to occur in bacteria?
General transcription factors are necessary for transcription to occur. In bacteria, transcription initiation requires an RNA polymerase and a single GTF: sigma factor . In archaea and eukaryotes, transcription initiation requires an RNA polymerase and a set of multiple GTFs to form a transcription preinitiation complex.