Search results
Results from the WOW.Com Content Network
A typical operon. In genetics, an operon is a functioning unit of DNA containing a cluster of genes under the control of a single promoter. [1] The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo splicing to create monocistronic mRNAs that are translated separately, i.e. several strands of mRNA that each encode a single gene product.
Activator binds to an inducer and the complex binds to the activation sequence and activates target gene. [2] Removing the inducer stops transcription. [2] Because a small inducer molecule is required, the increased expression of the target gene is called induction. [2] The lactose operon is one example of an inducible system. [2]
Other regulatory genes code for activator proteins. An activator binds to a site on the DNA molecule and causes an increase in transcription of a nearby gene. In prokaryotes, a well-known activator protein is the catabolite activator protein (CAP), involved in positive control of the lac operon.
The breakdown of maltose in Escherichia coli is controlled by gene activation. [3] The genes that code for the enzymes responsible for maltose catabolism can only be transcribed in the presence of an activator. [3] The activator that controls transcription of the maltose enzymes is "off" in the absence of maltose. [3]
The splice isoform DNMT3A2 behaves like the product of a classical immediate-early gene and, for instance, it is robustly and transiently produced after neuronal activation. [26] Where the DNA methyltransferase isoform DNMT3A2 binds and adds methyl groups to cytosines appears to be determined by histone post translational modifications.
This is a biological circuit where a simple repressor or promoter is introduced to facilitate creation of the product, or inhibition of a competing pathway. However, with the limited understanding of cellular networks and natural circuitry, implementation of more robust schemes with more precise control and feedback is hindered.
upregulation, activation, or promotion – increase the rate of gene transcription downregulation , repression , or suppression – decrease the rate of gene transcription coactivator – a protein (or a small molecule) that works with transcription factors to increase the rate of gene transcription
The L-arabinose operon, also called the ara or araBAD operon, is an operon required for the breakdown of the five-carbon sugar L-arabinose in Escherichia coli. [1] The L-arabinose operon contains three structural genes: araB, araA, araD (collectively known as araBAD), which encode for three metabolic enzymes that are required for the metabolism of L-arabinose. [2]