Repressible Genes
Repressible Genes - Related Videos
04:25
Reporter Gene Repression Assay to Study Translational Regulation of a Target Gene
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2025
This video demonstrates an in vivo assay in bacteria to study the interaction of RNA-binding proteins (RBPs) with RNA. The bacterial cells are transformed with two plasmid constructs — a binding-site plasmid encoding an mRNA containing a fluorescent reporter gene downstream of an RBP-binding site — while an RBP plasmid expresses the RBP proteins under the control of an inducer. Upon inducer-mediated increase in RBP production, the RBPs bind to the mRNA, resulting in translational repression of...
07:27
CRISPR Interference-Based Gene Silencing: A Technique for Targeted Repression of Gene Function in Pathogenic Leptospira
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2025
This video demonstrates a CRISPR interference-based gene silencing in pathogenic Leptospira. Targeted repression of gene expression using a CRISPR/Cas system that blocks mRNA formation helps identify candidate genes for pathological and pharmacological studies.
10:28
Repressing Gene Transcription by Redirecting Cellular Machinery with Chemical Epigenetic Modifiers
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Cited by 7 •
2018
Regulation of the chromatin environment is an essential process required for proper gene expression. Here, we describe a method for controlling gene expression through the recruitment of chromatin-modifying machinery in a gene-specific and reversible manner.
01:16
Repressed Memory
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2025
Repressed memories are a psychological phenomenon where memories of traumatic events are unconsciously blocked from a person's awareness. This process occurs as a defense mechanism, protecting the mind from the emotional impact of distressing or painful experiences. For example, a person who has experienced childhood trauma may grow up with no conscious recollection of the event. In such cases, the memories are thought to be buried deep within the subconscious, inaccessible to the conscious...
01:21
Repressible Operon: trp Operon
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2025
The trp operon in Escherichia coli exemplifies a repressible operon. It regulates the synthesis of tryptophan through repressor-mediated transcriptional control and attenuation. This dual regulatory mechanism ensures tryptophan biosynthesis occurs only when needed, conserving cellular resources.Structure of the trp OperonThe trp operon consists of five structural genes (trpE, trpD, trpC, trpB, and trpA) that encode enzymes for tryptophan biosynthesis. These genes are transcribed as a single...
FAQs
The corepressor binds to the repressor protein and changes its three-dimensional shape. This conformational change enables the repressor to recognize and bind the operator, a regulatory DNA region positioned so that bound repressor can prevent RNA polymerase from transcribing the associated genes. The signal therefore controls transcription indirectly through protein structure and DNA binding.
Abundant end product signals that the cell already has sufficient output from a biosynthetic pathway. Acting as a corepressor, the product helps the repressor bind the operator and reduce transcription of pathway genes. This feedback arrangement limits further production and conserves cellular energy and raw materials when metabolic demand is low.
When the pathway’s end product is not abundant, it is less available to act as a corepressor. The repressor therefore remains unable to adopt the operator-binding state described for the active regulatory complex. Transcription can continue, allowing the genes associated with biosynthesis to remain available when the cell needs additional pathway output.
The operator provides the DNA control point at which the activated repressor acts. Once the corepressor has changed the repressor’s shape, the resulting complex binds this region and blocks RNA polymerase from transcribing the associated genes. Operator control links the chemical signal from metabolism to a direct change in gene expression.
A useful analysis follows the relationship among four elements: the biosynthetic end product, the repressor protein, the operator, and RNA polymerase. Researchers can then ask whether product abundance changes repressor activity and whether operator binding alters transcription. Considering these components together reveals how metabolic feedback produces coordinated gene control.
They provide a model for understanding how cells match gene activity to metabolic conditions. Their regulation illustrates feedback control, energy conservation, adaptive responses, and coordinated biosynthesis, especially in bacteria. Studying these genes and their operons helps connect molecular events at regulatory DNA with broader changes in cellular resource use and metabolism.