The lac operator is present only in lac operon and it interacts specifically with
Answers
Million operation
The lactose operations of E. coli include gene involved in lactose metabolism. This is expressed when lactose is present and glucose is absent.
Million repressor serves as a lactose sensor. It usually blocks the transformation of the open, but lactose stops working as a suppressor when it is present. Lac repressor feels lactose indirectly through its isomer allococcus.
LAC Operon is a group of genes with a single promoter (written as a single MRNA). Open-encoded proteins allow genes that allow bacteria to use lactose as an energy source.
Structure of lakh operation
There are three genes in the million operations: LACZ, LACI, and LACA. These genes are written in the form of a single mRNA under the control of a promoter.
Genes in the million operations specify proteins that help the cell to use lactose. lacZencodes is an enzyme which divides lactose into monosacsaide (single-unit sugars) which can be fed into glycolysis. LacY, similarly, encodes a membrane-embedded transporter that helps in bringing lactose to the cell.
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In addition to the three genes, there are several regulatory DNA sequences in the million operations. These are areas of DNA for which special regulatory proteins can be bound, can control the transcription of the operation.
• The promoter RNA is the binding site for polymerase, the enzyme that transcriptions.
• The operator is a negative regulatory site which is bound by the LAC repressor protein. The operator overlaps with the promoter, and when the lacrpresser is bound, RNA can not connect with the polymerase promoter and can not start transcription.
• CAP binding site is a positive regulatory site that is bound to the CatLight Activator Protein (CAP). When CAP is tied to this site, then it promotes transcription by helping the promoter to build RNA polymerase.
Answer:
The lactose operon (lac operon) is an operon required for the transport and metabolism of lactose in E.coli and many other enteric bacteria. Although glucose is the preferred carbon source for most bacteria, the lac operon allows for the effective digestion of lactose when glucose is not available through the activity of beta-galactosidase.[1] Gene regulation of the lac operon was the first genetic regulatory mechanism to be understood clearly, so it has become a foremost example of prokaryotic gene regulation. It is often discussed in introductory molecular and cellular biology classes for this reason. This lactose metabolism system was used by François Jacob and Jacques Monod to determine how a biological cell knows which enzyme to synthesize. Their work on the lac operon won them the Nobel Prize in Physiology in 1965.[1]
Bacterial operons are polycistronic transcripts that are able to produce multiple proteins from one mRNA transcript. In this case, when lactose is required as a sugar source for the bacterium, the three genes of the lac operon can be expressed and their subsequent proteins translated: lacZ, lacY, and lacA. The gene product of lacZ is β-galactosidase which cleaves lactose, a disaccharide, into glucose and galactose. lacY encodes Beta-galactoside permease, a membrane protein which becomes embedded in the cytoplasmic membrane to enable the cellular transport of lactose into the cell. Finally, lacA encodes Galactoside acetyltransferase.