lactose operon


lactose operon
Group of adjacent and coordinately controlled genes concerned with the metabolism of lactose in E. coli. The lac operon was the first example of a group of genes under the control of an operator region to which a lactose repressor binds. When the bacteria are transferred to lactose-containing medium, allolactose (which forms by transglycosylation when lactose is present in the cell) binds to the repressor, inhibits the binding of the repressor to the operator, and allows transcription of mRNA for enzymes involved in galactose metabolism and transport across the membrane (beta-galactosidase, galactoside permease, and thiogalactoside transacetylase). LacZ codes for beta-galactosidase, lacY for the permease, lacA for the transacetylase.

Dictionary of molecular biology. 2004.

Look at other dictionaries:

  • lactose operon — lactose operon. См. lас оперон. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Lactose-Operon — Das Lactose Operon, kurz lac Operon, ist ein Operon, das sowohl beim Transport, als auch beim Abbau von Lactose in Bakterien, beispielsweise Escherichia coli, eine wichtige Rolle spielt. Inhaltsverzeichnis 1 Aufbau des Operons 2 Regulation des… …   Deutsch Wikipedia

  • lactose carrier protein — The best known example is the product of the lacY gene, coded for in the lactose operon and responsible for the uptake of lactose by E. coli …   Dictionary of molecular biology

  • lactose repressor — Protein (tetramer of 37 kD subunits) that normally binds with very high affinity to the operator region of the lactose operon and inhibits transcription of the downstream genes by blocking access of the polymerase to the promoter region. When the …   Dictionary of molecular biology

  • Operon — Opéron Un opéron est un groupement de gènes et de séquences régulatrices du génome des procaryotes chez qui cette organisation est principalement rencontrée. Les gènes concourent à la réalisation d une même fonction physiologique et sont… …   Wikipédia en Français

  • Opéron lactose — Colonies d E. coli sur une boîte de Petri contenant du X gal, donnant leur couleur bleue aux colonies produisant la β galactosidase et catabolisant donc le lactose. L opéron lactose, ou opéron lac est un opéron nécessaire au transport et au …   Wikipédia en Français

  • Operon — A typical operon In genetics, an operon is a functioning unit of genomic DNA containing a cluster of genes under the control of a single regulatory signal or promoter.[1][2] The genes are tr …   Wikipedia

  • operon — A genetic functional unit that controls production of a messenger RNA; it consists of an operator gene and two or more structural genes located in sequence in the cis position on one chromosome. [L. operor, to work, act, + on] Lac o …   Medical dictionary

  • operon — /op euh ron /, n. Genetics. a set of two or more adjacent cistrons whose transcription is under the coordinated control of a promoter, an operator, and a regulator gene. [1960 65; < F opéron, equiv. to opér(er) to work, OPERATE + on ON1] * * *… …   Universalium

  • Operón lac — Este artículo o sección necesita referencias que aparezcan en una publicación acreditada, como revistas especializadas, monografías, prensa diaria o páginas de Internet fidedignas. Puedes añadirlas así o avisar …   Wikipedia Español


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.