Lac operon
... lac operon in NCBI Bookshelf [2] Virtual Cell Animation Collection Introducing: The Lac Operon The lac Operon: Bozeman Science ... The lactose operon (lac operon) is an operon required for the transport and metabolism of lactose in E. coli and many other ... In the absence of lactose, the lac repressor, lacI, halts production of the enzymes encoded by the lac operon. The lac ... lac p, and the lac operator, lac o. Although it is not strictly standard usage, mutations affecting lac o are referred to as ...
Gal operon
The gal operon is also controlled by CRP-cAMP, similarly to the lac operon. CRP-cAMP binds to the -35 region, promoting ... lac operon Weickert, M. J.; Adhya, S. (October 1993). "The galactose regulon of Escherichia coli". Molecular Microbiology. 10 ( ... The gal operon is a prokaryotic operon, which encodes enzymes necessary for galactose metabolism. Repression of gene expression ... The gal operon contains two operators, OE (for external) and OI (for internal). The former is just upstream of the promoter, ...
Nik operon
gene regulation Operon lac operon Navarro, Clarisse; Wu, Long-Fei; Mandrand-Berthelot, Marie-Andrée (1 September 1993). "The ... The nik operon is an operon required for uptake of nickel ions into the cell. It is present in many bacteria, but has been ... Nickel ion concentration in the cell is regulated through the nik operon. The nik operon consists of six genes. The first five ... The following table summarizes the structure of the nik operon: Regulation of expression of the nikR gene is achieved by two ...
Galactoside acetyltransferase
It is coded for by the lacA gene of the lac operon in E. coli. It catalyzes the following reaction: acetyl-CoA + beta-D- ... The enzyme's role in the classical E.coli lac operon remains unclear. However, the enzyme's cellular role may be to detoxify ... Transacetylase Wang XG, Olsen LR, Roderick SL (April 2002). "Structure of the lac operon galactoside acetyltransferase". ... Roderick SL (June 2005). "The lac operon galactoside acetyltransferase". Comptes Rendus Biologies. 328 (6): 568-75. doi:10.1016 ...
Gal4 transcription factor
... lac operon Klar AJ, Halvorson HO (1974). "Studies on the positive regulatory gene, GAL4, in regulation of galactose catabolic ...
Inducer
... the lac operon is repressed. This is because glucose actively prevents the induction of lacZYA. In the ara operon (also known ... The inducer in the lac operon is allolactose. If lactose is present in the medium, then a small amount of it will be converted ... The lactose operon is one example of an inducible system. Repressor proteins bind to the DNA strand and prevent RNA polymerase ... RNA polymerase can then begin to transcribe operon genes. By binding to activators. Activators generally bind poorly to ...
Growth medium
X-gal plates are differential for lac operon mutants. Transport media should fulfill these criteria: Temporary storage of ...
Phenyl-D-galactopyranoside
Lac operon Fischer L, Scheckermann C, Wagner F (April 1995). "Purification and characterization of a thermotolerant beta- ...
Kathleen Matthews (biochemist)
... and investigated how cystein thiol groups within the lac repressor core directly interacted with the lac operon, initially ... Müller-Hill, Benno (May 12, 2011). The Lac Operon A Short History of a Genetic Paradigm. De Gruyter. pp. 99-101. ISBN ... that the four core regions in each of the homotetramer lac repressor protein were all required for binding with the lac operon ... Matthews' research focused on the interactions of protein and DNA, in particular lac repressor and the Hox gene protein ...
Structural gene
Model of Lac Operon The SGC protein browser SILVA database of aligned rRNA sequence data Barcode of Life database of COI ... This is best illustrated by the well-studied lac operon, in which three structural genes (lacZ, lacY, and lacA) are all ... Müller-Hill, Benno (1996-01-01). The Lac Operon: A Short History of a Genetic Paradigm. Walter de Gruyter. ISBN 9783110148305. ... The distinction between regulatory and structural genes can be attributed to the original 1959 work on Lac operon protein ...
Lac repressor
Lac operon Schumacher MA, Choi KY, Zalkin H, Brennan RG (November 1994). "Crystal structure of LacI member, PurR, bound to DNA ... They showed that in vitro the protein bound to DNA containing the lac operon, and it released the DNA when IPTG (an analog of ... Oehler S, Eismann ER, Krämer H, Müller-Hill B (April 1990). "The three operators of the lac operon cooperate in repression". ... Goodsell DS (2003). "Lac Repressor". RCSB Protein Data Bank. doi:10.2210/rcsb_pdb/mom_2003_3. Lewis M (June 2005). "The lac ...
Arthur Riggs (geneticist)
72 Müller-Hill, Benno (1996). The lac Operon : a short history of a genetic paradigm. New York: Walter de Gruyter. ISBN 978-3- ... They hoped to mix E. coli lac repressor with lac operator, crystallize it, and examine the protein-DNA binding of the crystals ... the lambda repressor and the lac repressor. Riggs worked on isolating the lac repressor by affinity chromatography. Walter ... They were able to clone Itakura's lac operator and confirm that it would work in live bacteria, an important result. They also ...
Gene
... when the repressor is inactive transcription of the operon can occur (see e.g. Lac operon). The products of operon genes ... The regulation of lactose metabolism genes in E. coli (lac operon) was the first such mechanism to be described in 1961. A ... The genes in an operon are transcribed as a continuous messenger RNA, referred to as a polycistronic mRNA. The term cistron in ... The transcription of an operon's mRNA is often controlled by a repressor that can occur in an active or inactive state ...
Operon
This allows for expression of the operon. The lac operon is a negatively controlled inducible operon, where the inducer ... The first operon to be described was the lac operon in E. coli. The 1965 Nobel Prize in Physiology and Medicine was awarded to ... The lac operon of the model bacterium Escherichia coli was the first operon to be discovered and provides a typical example of ... While the lac operon can be activated by a chemical (allolactose), the tryptophan (Trp) operon is inhibited by a chemical ( ...
Galactose
The latter is produced by the lac operon in Escherichia coli.[citation needed] In nature, lactose is found primarily in milk ...
Lactose permease
It is encoded by the lacY gene in the lac operon. The LacY gene is a component of the lac operon that encodes lactose permease ...
Transcription-translation coupling
Newton, W. A.; Beckwith, J. R.; Zipser, D. & Brenner, S. (1965). "Nonsense mutants and polarity in the lac operon of ... The term "attenuation" was introduced to describe the his operon. While it is typically used to describe biosynthesis operons ... The trp operon is regulated by both attenuation and repression, and was the first evidence that gene expression regulation ... Johnston, H. M.; Barnes, W. M.; Chumley, F. G.; Bossi, L. & Roth, J. R. (1980). "Model for regulation of the histidine operon ...
Catabolite activator protein
Julian Davies (microbiologist)
At the Institute Pasteur he established his molecular biology credentials by mapping the i and o genes of the lac operon. At ... Davies, Julian; Jacob, François (28 September 1968). "Genetic mapping of the regulator and operator genes of the lac operon". ...
Synthetic biological circuit
The lac operon is used in the biotechnology industry for production of recombinant proteins for therapeutic use. The gene or ... The first natural gene circuit studied in detail was the lac operon. In studies of diauxic growth of E. coli on two-sugar media ... function was a two-part control mechanism on the lac operon. When lactose is present in the cell the enzyme β-galactosidase is ... When lactose is absent in the cell the lac repressor inhibits the production of the enzyme β-galactosidase to prevent any ...
Positive feedback
A classic example of positive feedback is the lac operon in E. coli. Positive feedback plays an integral role in cellular ...
Diauxic growth
Monod later put aside his work on diauxic growth and focused on the lac operon model of gene expression, which led to a Nobel ... During his work on the lac operon of E. coli, Joshua Lederberg isolated β-galactosidase and found it in greater quantities in ... Thus, if glucose is present, cAMP levels remain low, so CAP is unable to activate transcription of the lac operon, regardless ... This process can also refer to the positive control of the lac operon. Editors, AccessScience (2015). "Diauxic growth (diauxie ...
Cyclic adenosine monophosphate
cAMP, for example, is involved in the positive regulation of the lac operon. In an environment with a low glucose concentration ... With a high glucose concentration, the cAMP concentration decreases, and the CRP disengages from the lac operon. Since cyclic ... making it easier for RNA polymerase to bind to the adjacent promoter to start transcription of the lac operon, increasing the ... The protein assumes its active shape and binds to a specific site upstream of the lac promoter, ...
Lactose
Regulation of gene expression
The Lac operon is an interesting example of how gene expression can be regulated. Viruses, despite having only a few genes, ... The image to the right demonstrates regulation by a repressor in the lac operon. General transcription factors position RNA ... the first discovery of a gene regulation system is widely considered to be the identification in 1961 of the lac operon, ...
Vector (molecular biology)
Other strong promoters used include Trp promoter and Tac-Promoter, which are a hybrid of both the Trp and Lac Operon promoters ... Promoter - commonly used inducible promoters are promoters derived from lac operon and the T7 promoter. ...
Cis-regulatory element
An example of a cis-acting regulatory sequence is the operator in the lac operon. This DNA sequence is bound by the lac ... The lac operator is, thus, considered to "act in cis" on the regulation of the nearby genes. The operator itself does not code ... Operators are CREs in prokaryotes and some eukaryotes that exist within operons, where they can bind proteins called repressors ... mRNA Other Regulation of gene expression Cis-trans isomerism Gene regulatory network Operon Promoter Trans-acting factor Rfam ...
Susan Gottesman
Previous studies had only shown success in the lac operon, but the lambda phage was successful for the arabinose operon in her ... Their work involved studying the lac operon to further understand the E. coli arabinose operon. From their research, they were ... able to show that a transducing bacteriophage could work for the arabinose operon. ...
Blue-white screen
β-galactosidase is a protein encoded by the lacZ gene of the lac operon, and it exists as a homotetramer in its active state. ... It should also be understood that the lac operon is affected by the presence of glucose. The protein EIIAGlc, which is involved ... Isopropyl β-D-1-thiogalactopyranoside (IPTG), which functions as the inducer of the lac operon, may be used in the media to ... Insertion of a HindII fragment of the lac regulatory region in M13 replicative form in vitro". Proceedings of the National ...
Catabolite repression
cAMP binds to catabolite activator protein (CAP) and together they will bind to a promoter sequence on the lac operon. However ... Next, bacteria start to transcribe the lac operon and produce β-galactosidase enzymes for lactose metabolism. The example above ... In this alternative pathway CcpA negatively represses other sugar operons so they are off in the presence of glucose. It works ... and when Hpr is phosphorylated it can then allow CcpA to block transcription of the alternative sugar pathway operons at their ...