Examples of transcription in the following topics:
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- In bacteria, transcription and translation are capable of proceeding simultaneously.
- Transcription-attenuation is characterized by the presence of 5'-cis acting regulatory regions that fold into alternative RNA structures which can terminate transcription.
- These RNA structures dictate whether transcription will proceed successfully or be terminated early, specifically, by causing transcription-attenuation.
- This characterizes the mechanisms of transcription-attenuation.
- This schematic represents transcriptional-attenuation as the formation of mRNA stem-loops prevents the continuance of transcription based on the levels of tryptophan in the metabolic environment.
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- Sigma factors are proteins that function in transcription initiation .
- Sigma factor synthesis is controlled at the levels of both transcription and translation.
- If transcription of genes involved in growth is necessary, the sigma factors will be translated to allow for transcription initiation to occur.
- However, if transcription of genes is not required, sigma factors will not be active.
- The anti-sigma factors are responsible for regulating inhibition of transcriptional activity in organisms that require sigma factor for proper transcription initiation.
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- Prokaryotic transcription is the process in which messenger RNA transcripts of genetic material in prokaryotes are produced, to be translated for the production of proteins.
- Prokaryotic transcription occurs in the cytoplasm alongside translation .
- Prokaryotic transcription and translation can occur simultaneously.
- Transcription is controlled by a variety of regulators in prokaryotes.
- Additional transcription regulation comes from transcription factors that can affect the stability of the holoenzyme structure at initiation.
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- Transcription and translation in archaea resemble these processes in eukaryotes more than in bacteria.
- The proteins that archaea, bacteria and eukaryotes share form a common core of cell function, relating mostly to transcription, translation, and nucleotide metabolism.
- Transcription and translation in archaea resemble these processes in eukaryotes more than in bacteria, with the archaean RNA polymerase and ribosomes being very close to their equivalents in eukaryotes.
- Although archaea only have one type of RNA polymerase, its structure and function in transcription seems to be close to that of the eukaryotic RNA polymerase II, with similar protein assemblies (the general transcription factors) directing the binding of the RNA polymerase to a gene's promoter.
- However, other archaean transcription factors are closer to those found in bacteria.
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- Primer extension can be used to determine the start site of RNA transcription for a known gene.
- First, it is used for mapping the 5' end of transcripts.
- This allows one to determine the transcription initiation site (assuming the mRNA isn't further processed), which helps localize promoters or TATA boxes .
- Second, it can be used to quantify the amount of transcript in an in vitro transcription system.
- This is a diagram of transcription initiation by the RNA polymerase.
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- Attenuation is a regulatory feature found throughout Archaea and Bacteria domains which causes premature termination of transcription.
- It is based on the fact that, in bacteria, transcription and translation can and do proceed simultaneously.
- Attenuation is a regulatory feature found throughout Archaea and Bacteria causing premature termination of transcription.
- The folding is modulated by a sensing mechanism producing either a Rho-independent terminator, resulting in interrupted transcription and a non-functional RNA product; or an anti-terminator structure, resulting in a functional RNA transcript.
- Attenuator is a nucleotide sequence in DNA that can lead to premature termination of transcription.
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- Transcriptional regulation occurs in several ways .
- Through SSM the TA repeat region can undergo addition or subtraction of TA dinucleotides which results in the reversible ON phase or OFF phase of transcription of the hifA and hifB.
- The second way that SSM induces transcriptional regulation is by changing the short repeat sequences located outside the promoter.
- It can also lead to differences in post-transcriptional stability of mRNA.
- Purple ovals can either be a transcription factor (TF) or RNA polymerase (RNAP).
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- Repression of anabolic pathways is regulated by altering transcription rates.
- Transcriptional regulation is the change in gene expression levels by altering transcription rates.
- Regulation of transcription controls when transcription occurs and how much RNA is created.
- Transcription of a gene by RNA polymerase can be regulated by at least five mechanisms:
- Activators bind to the upstream portion of the promoter, such as the CAP region (completely upstream from the transcript).
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- Sigma factors are groups of proteins that regulate transcription and therefore function in house-keeping, metabolic, and regulation of growth processes in bacteria.
- The regulation of expression of sigma factors occurs at transcriptional, translational, and post-translational levels as dictated by the cellular environment and the presence or absence of numerous cofactors.
- Using RpoS proteins as the focus, the RpoS expression and transcription is regulated at the translational level.
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- Prokaryotic transcription is the process in which messenger RNA transcripts of genetic material are produced for later translation into proteins.
- The transcription process includes the following steps: initiation, elongation and termination .
- For example, the antimicrobial rifampin binds to DNA-dependent RNA polymerase, thereby inhibiting the initiation of RNA transcription.