repressor

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Related to Repressors: repressor gene, aporepressor

repressor:

see nucleic acidnucleic acid,
any of a group of organic substances found in the chromosomes of living cells and viruses that play a central role in the storage and replication of hereditary information and in the expression of this information through protein synthesis.
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Repressor

 

a special regulating protein formed in bacterial cells that halts transcription, which is the synthesis of messenger ribonucleic acid (m-RNA) from a specific operon (a group of genes that carry out the synthesis of functionally related enzymes). The number of different repressors corresponds to the number of operons.

Unlike other proteins, a repressor present in a cell consists of ten to 20 molecules. The synthesis of m-RNA ceases when a repressor combines with an operator, which is the regulating part of an operon. An effector, for example, lactose in a lactose operon, interacts with a repressor to form a complex that inactivates and produces a reversible spatial change in a repressor molecule. This type of repressor can no longer combine with an operator and, as a result, m-RNA synthesis resumes.

repressor

[ri′pres·ər]
(biochemistry)
An end product of metabolism which represses the synthesis of enzymes in the metabolic pathway.
(genetics)
The product of a regulator gene that acts to repress the transcription of another gene.
References in periodicals archive ?
The main goal of this project was to initiate a structure-function study on the repressor protein of phage [epsilon]34.
The best examples of the effects of allosteric effectors on TF function are allolactose on the lac repressor interaction with DNA and steroids on nuclear factors.
The top 3 overall activators and repressors are separated to illustrate that the general effect that these transcription factors exert on their targets is analogous to Figure 5.
Absence of gntP, gntZ transcription, and reduced level of gntK transcription in presence of glucose and transcription of all four genes in the presence of gluconate implied that Sco1678 is a gluconate-dependent repressor for the transcription of gnt genes.
Their findings, published September 28 in Nature, show that over evolutionary time, primate genomes have undergone repeated episodes in which mutations in jumping genes allowed them to escape repression, which drove the evolution of new repressor genes, and so on.
Isolated islets from these rats display high levels of CREM repressor including ICER I, indicating that the increase of ICER could contribute to [beta]-cell dysfunction.
Thus, we investigated differences in suppression of the recall of visual images between repressors and nonrepressors using the TNT paradigm.
Because of their need for control, repressors are very disciplined and more motivated to adapt their lifestyles, Mund said.
Global regulators for carbon metabolism: CRP (cAMP receptor protein) and Cra (catabolite repressor activator).
Days later, the CCS said, "The 696 repressors identified by the CVJ and still enjoying impunity are the Praetorian Guard of a society that we want to change, in the same way that our disappeared companions wanted to change it and the landless campesinos today want to change it."
Assemblies of inflatable lungs/choked out of recognizable life/a rebel's reticence to ceasing/ as they cried out to canoes of mercy/rowed through canals of men with guns/as they cried out to the helicopters/ hovering ominously above their beloved communities/as they cried out save my grandmother my uncle/my auntie/ my babies/The repressors of their very movement they implored to find a human ringer/in the biliously murderous waters and even further appeals/ to secret emissaries authoring this snivelling siege of decriminalized killing/they resigned also to cry mercy
Why and how elites make the transition from innovators to repressors is complicated: the nature of the elitist threat changes from discipline to discipline, Lloyd suggests, because the potential that innovations possess to overturn an entire body of thought also changes from discipline to discipline.