Name: bacterial rna polymerase steps
Uploaded: 2023-04-30T10:13:44.000Z
Duration: 1 min 53 s
Channel: JoVE

To initiate transcription, the RNA polymerase holoenzyme binds non-specifically to the DNA with low affinity. It then slides along the DNA to locate the promoter sequence.&#160;
When it slides into the promoter, specifically the -10 and the -35 regions upstream of the initiation site, the sigma subunit of the RNA polymerase binds to the promoter tightly and unwinds the DNA to form the &#8216;open-promoter&#8217; complex.&#160;
The RNA polymerase holoenzyme, now positioned at the transcription initiation site, synthesizes the RNA transcript by adding the complementary nucleotides to the DNA template. Once a 10-nucleotide long RNA chain has been synthesized, the sigma factor gets released.&#160;
The RNA polymerase core enzyme continues to add nucleotides to the growing RNA transcript. As the polymerase moves forward, DNA is continuously unwound ahead of the enzyme and rewound behind it.
The process continues until the gene is transcribed and the core polymerase encounters the termination signal. The most common termination signal is a symmetrical inverted repeat of a GC-rich sequence followed by a poly-A tail.
When this sequence is transcribed into RNA, the self-complementary sequence base-pairs to form a stab

bacterial transcription

Bacterial Transcription

RNA polymerase (RNAP) carries out DNA-dependent RNA synthesis in both bacteria and eukaryotes. Bacteria do not have a membrane-bound nucleus. So, transcription and translation occur simultaneously, on the same DNA template.
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
<ol>
	<li>Initiation, which involves two specific sequences 10 and 35 base pairs upstream of the gene, which are called promoters.</li>
	<li>Elongation, where the polymerase proceeds along the DNA template, synthesizing mRNA in the 5&#39;&#160;to 3&#39;&#160;direction.</li>
	<li>Termination, in which the polymerase encounters a region rich in C-G nucleotides and stops mRNA synthesis.</li>
</ol>
Bacterial RNAP carries out all three steps in conjunction with other accessory proteins. Transcription starts at a DNA base pair that is conventionally numbered +1. Base pairs along the direction of transcription are termed to be downstream of the start site and are denoted with positive numbers. Basepairs in the opposite direction are said to be upstream and are denoted with negative numbers. Transcription begins when the RNAP binds the promoter sequences forming a closed complex. At this stage, the template DNA strands are still base-paired. To transition to the elongation stage, the RNAP breaks the hydrogen bonds between the base pairs and binds tightly to the single-stranded DNA at the start site. This is called an open complex, which can now carry out mRNA synthesis.

RNA polymerase (RNAP) carries out DNA-dependent RNA synthesis in both bacteria and eukaryotes. Bacteria do not have a membrane-bound nucleus. So, ...

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JoVE Core

Molecular Biology

Unit 1

Transcription: DNA to RNA

KEY TERMS AND CONCEPTS

bacterial rna polymerase steps

Bacterial RNA polymerase carries out RNA synthesis from DNA. In bacteria, there is no membrane-bound nucleus. As a result, transcription and translation can happen at the same time on the same DNA template.

Bacterial transcription has three main stages: initiation, elongation, and termination. These stages are guided by specific DNA sequences. The promoter regions lie 10 and 35 base pairs upstream of the gene and help RNAP begin transcription.

Transcription starts at the DNA base pair labeled +1. Bases in the direction of transcription are called downstream and use positive numbers. Bases on the opposite side are upstream and use negative numbers.

During initiation, RNAP binds the promoter sequences and forms a closed complex. At this point, the DNA strands are still paired. RNAP then breaks the hydrogen bonds, separates the strands, and binds tightly to the single-stranded DNA at the start site. This open complex can move into elongation and make mRNA in the 5' to 3' direction.

Termination happens when RNAP reaches a region rich in C-G nucleotides. At that point, mRNA synthesis stops. Bacterial RNAP carries out these steps with the help of other accessory proteins.

Bacterial RNA Polymerase Steps

what is gene expression?

Gene Expression: From DNA to Proteins

Gene expression is the process that uses DNA instructions to make proteins. Proteins help cells do many of their jobs, so gene expression is a key part of how cells work. The process starts with transcription, when a gene’s DNA sequence is copied into RNA. In eukaryotic cells, this RNA is then processed by splicing. Splicing removes noncoding regions and joins the coding parts of the message. After transcription and splicing, the RNA is ready for translation. During translation, the cell...

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bacterial rna polymerase

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transcription

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Transcription Regulators and Chromatin Access

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eukaryotic rna polymerases

RNA Polymerase II and mRNA Termination

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transcription elongation factors

RNA Polymerase Pausing in Elongation

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pre-mrna processing

Pre-mRNA Splicing and RNA Protection

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RNA Splicing and the Spliceosome

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chromatin structure regulates pre-mrna processing

chromatin-structure-regulates-pre-mrna-processing

How Chromatin Shapes mRNA Splicing

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nuclear export of mrna

mRNA Quality Control Before Export

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How Ribosomes Are Assembled in Cells

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tRNA Modified Bases and Function

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Nucleolus Structure and Ribosome Assembly

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Bacterial RNA polymerase carries out RNA synthesis from DNA. In bacteria, there is no membrane-bound nucleus. As a result, transcription and translation can happen at the same time on the same DNA template. Bacterial transcription has three main stages: initiation, elongation, and termination. These stages are guided by specific DNA sequences. The promoter regions lie 10 and 35 base pairs upstream of the gene and help RNAP begin transcription. Transcription starts at the DNA base pair labeled...

transcription initiation

RNA Polymerase Recruitment in Transcription

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key terms and concepts

Learn how bacterial RNA polymerase starts at promoters, forms closed and open complexes, builds mRNA 5' to 3', and stops at C-G rich regions.

Bacterial RNA Polymerase Steps | JoVE K12

molecular biology

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Bacterial RNA Polymerase Steps

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