Intrinsic Termination
Intrinsic Termination - Related Videos
02:18
Intrinsically Disordered Proteins
0 Views •
2020
Intrinsically disordered proteins are a group of proteins that do not fold into specific three-dimensional structures. Their structural flexibility allows them to complement ordered proteins to perform functions that are inaccessible to rigid structures. They are more common in eukaryotes than prokaryotes and may either be exclusively intrinsically disordered or hybrid proteins, consisting of a mix of ordered and disordered regions. The absence of a rigid structure in these proteins can be...
02:18
Intrinsically Disordered Proteins
0 Views •
2023
Intrinsically disordered proteins are a group of proteins that do not fold into specific three-dimensional structures. Their structural flexibility allows them to complement ordered proteins to perform functions that are inaccessible to rigid structures. They are more common in eukaryotes than prokaryotes and may either be exclusively intrinsically disordered or hybrid proteins, consisting of a mix of ordered and disordered regions. The absence of a rigid structure in these proteins can be...
01:44
Termination of Translation
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2020
The large ribosomal subunit has several important structures essential to translation. These include the peptidyl transferase center (PTC) - which is the site where the peptide bond is formed - and a large, internal, water-filled tube through which the nascent polypeptide moves. This latter structure is called the Peptide Exit Tunnel, and it begins at the PTC and spans the body of the large ribosomal subunit. During translation, as the nascent polypeptide chain is synthesized, it passes through...
01:31
The Intrinsic Apoptotic Pathway
0 Views •
2023
Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
15:16
Loading Drosophila Nerve Terminals with Calcium Indicators
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Cited by 17 •
2007
Calcium is a ubiquitous messenger in the nervous system, essential for triggering neurotransmitter release and changes in synaptic strength. Here we demonstrate a technique for loading Ca2+-indicators into Drosophila nerve terminals. We also demonstrate fabrication of the required apparatus and emphasize points critical for the technique's success.
FAQs
The hairpin forms in the emerging RNA when the transcript contains a terminator sequence capable of folding back on itself. Its stable structure interferes with continued movement of RNA polymerase and creates a pause at the termination site. This pause gives the nearby weak RNA-DNA hybrid, enriched in uracil and adenine, a role in promoting transcript release.
A weak RNA-DNA hybrid makes the transcription complex more susceptible to dissociation once the polymerase pauses. In this context, enrichment in uracil and adenine contributes to reduced stability at the point where release occurs. The combination of a paused polymerase, an RNA hairpin, and a weak hybrid helps define where transcription ends.
Intrinsic Termination relies on information encoded in the transcribed sequence and the structure formed by the emerging RNA, rather than requiring an external protein factor. The hairpin and weak RNA-DNA hybrid provide the relevant termination signals. This distinction is important when comparing mechanisms of transcription control across biological systems or interpreting bacterial regulatory sequences.
A mechanistic analysis should examine whether a transcribed terminator sequence can produce a stable RNA hairpin followed by a weak RNA-DNA hybrid enriched in uracil and adenine. It should also consider how these features could pause RNA polymerase and promote release. Together, sequence composition and predicted RNA structure help explain a termination outcome.
Researchers can relate terminator sequence features to transcript boundaries and the point at which RNA polymerase releases the RNA. Examining the hairpin, the downstream weak hybrid, and the resulting pause connects molecular structure with gene-expression control. This approach helps clarify how bacteria prevent unnecessary transcription beyond the intended end of a gene or regulatory region.
By defining transcript boundaries, Intrinsic Termination can help organize transcriptional units and limit unnecessary read-through. That makes the mechanism relevant to bacterial genome organization and to synthetic biology, where engineered genetic circuits require controlled expression boundaries. Understanding the sequence and structural requirements also supports designing or evaluating circuits that depend on predictable transcriptional shutoff.
Although it is primarily associated with bacteria, Intrinsic Termination also occurs in some organelles. This broader distribution makes the mechanism useful for studying how different biological systems establish transcript endpoints without relying on an external protein factor. Comparing bacterial and organelle contexts can connect transcriptional regulation with genome organization across distinct cellular compartments.