The lac operon: 1: RNA Polymerase, 2: lac repressor, 3: Promoter, 4: Operator, 5: Lactose, 6: lacZ, 7: lacY, 8: lacA.Top: The gene is essentially turned off. There is no lactose to inhibit the repressor, so the repressor binds to the operator, which obstructs the RNA polymerase from binding to the promoter and making lactase. Bottom: The gene is turned on. Lactose is inhibiting the repressor, allowing the RNA polymerase to bind with the promoter, and express the genes, which synthesize lactase. Eventually, the lactase will digest all of the lactose, until there is none to bind to the repressor. The repressor will then bind to the operator, stopping the manufacture of lactase.
In molecular genetics, a repressor is a DNA- or RNA-binding protein that inhibits the expression of one or more genes by binding to the operator or associated silencers. A DNA-binding repressor blocks the attachment of RNA polymerase to the promoter, thus preventing transcription of the genes into messenger RNA. An RNA-binding repressor binds to the mRNA and prevents translation of the mRNA into protein. This blocking or reducing of expression is called repression.
bind to the repressor and make it bind to the operator tightly, which decreases transcription. A repressor that binds with a co-repressor is termed an...
Tryptophan repressor (or trp repressor) is a transcription factor involved in controlling amino acid metabolism. It has been best studied in Escherichia...
allolactose binds to the lac repressor, causing an allosteric change in its shape. In its changed state, the lac repressor is unable to bind tightly to...
Repressor LexA or LexA (Locus for X-ray sensitivity A) is a transcriptional repressor (EC 3.4.21.88) that represses SOS response genes coding primarily...
either allolactose or IPTG, to the repressor affects the distribution of repressor between the two shapes. Thus, repressor with inducer bound is stabilized...
encodes two repressors: the Cro repressor that acts to turn off early gene transcription during the lytic cycle, and the lambda or cI repressor required...
The expression of Tc resistance genes is regulated by the repressor TetR. TetR represses the expression of TetA, a membrane protein that pumps out substances...
An enzyme repressor is a substance that negatively regulates the amount of an enzyme by decreasing the rate of its biosynthesis. It is the opposite of...
replication of the lambda genome (OP). Cro dominates the repressor site (see "Repressor" section), repressing synthesis from the PRM promoter (which is a promoter...
The Private Repress is a remix album by American hip hop producer DJ Shadow, released exclusively in Japan by Island Records on March 29, 2003. It contains...
the repressor gene (trp R) that binds to the operator. In the lac operon, lactose binds to the repressor protein and prevents it from repressing gene...
The Ribose repressor (RbsR) is a bacterial DNA-binding transcription repressor protein and a member of the LacI/GalR protein family. In Escherichia coli...
Rop (also known as repressor of primer, or as RNA one modulator (ROM)) is a small dimeric protein responsible for keeping the copy number of ColE1 family...
activating ligand of a repressor protein. For example, the E. coli tryptophan repressor (TrpR) is only able to bind to DNA and repress transcription of the...
repression, the down-regulation of gene transcription by the action of repressor proteins binding to a promoter "Repression" (Star Trek: Voyager), an episode...
present, these tryptophan repressor dimers bind to tryptophan, causing a change in the repressor conformation, allowing the repressor to bind to the operator...
transcriptional repressor of transporters for the import of manganese. Treponema pallidum troR, a metal-dependent transcriptional repressor. Archaeoglobus...
expression of the gene. The image to the right demonstrates regulation by a repressor in the lac operon. General transcription factors position RNA polymerase...
of the tetrameric lac repressor, which results in conformational changes and reduces the binding affinity of the lac repressor to the lac operator, thereby...
gene represses signal transduction by the AhR by competing with the arylhydrocarbon receptor for binding to the ARNT. Expression of the repressor is stimulated...
turns the gene on). Then there's the repressor protein that turns genes off. The inducer can remove this repressor, turning genes back on. The operator...
gene is a gene that codes for a repressor protein that inhibits the activity of an operator (a gene which binds repressor proteins thus inhibiting the translation...
implemented policy of socialist realism. The doctrine did not necessarily repress the use of the Ukrainian language, but it required that writers follow...
or disturbing public order (trouble à l'ordre public) have been used to repress public expressions of homosexuality or street prostitution.[citation needed]...
disabling repressors. The gene is expressed because an inducer binds to the repressor. The binding of the inducer to the repressor prevents the repressor from...
In molecular biology, the arginine repressor (ArgR) is a repressor of prokaryotic arginine deiminase pathways. The arginine dihydrolase (AD) pathway is...
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