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Gene regulation works using operators and repressors in bacteria. Gene Regulation can be summarized by the response of the respective system: Inducible systems - An inducible system is off unless there is the presence of some molecule (called an inducer) that allows for gene expression. The molecule is said to "induce expression".
Positive control elements that bind to DNA and incite higher levels of transcription. [3] While these means of transcriptional regulation also exist in eukaryotes, the transcriptional landscape is significantly more complicated both by the number of proteins involved as well as by the presence of introns and the packaging of DNA into histones.
The coupling between the two processes provides an important mechanism for prokaryotic gene regulation. [1] At the level of initiation, RNA polymerase in prokaryotes (bacteria in particular) binds strongly to the promoter region and initiates a high basal rate of transcription.
In DNA, regulation of gene expression normally happens at the level of RNA biosynthesis (transcription). It is accomplished through the sequence-specific binding of proteins (transcription factors) that activate or inhibit transcription. Transcription factors may act as activators, repressors, or both.
In eukaryotes, transcription is performed in the nucleus by three types of RNA polymerases, each of which needs a special DNA sequence called the promoter and a set of DNA-binding proteins—transcription factors—to initiate the process (see regulation of transcription below).
There are several differences in the regulation of metabolic control in eukaryotes and in prokaryotes. Prokaryotes vary the numbers of specific enzymes made in their cells in order to regulate gene expression, which is slow metabolic control, and also regulate enzymatic pathways through mechanisms such as feedback inhibition and allosteric ...
[2] [3] If the regulatory sequence is located far away, the DNA will loop over itself (DNA looping) in order for the bound activator to interact with the transcription machinery at the promoter site. [2] [3] In prokaryotes, multiple genes can be transcribed together , and are thus controlled under the same regulatory sequence. [2]
(By contrast, eukaryotic kinases are typically easily identified, but they are not easily paired with their substrates.) [3] A database of prokaryotic two-component systems called P2CS has been compiled to document and classify known examples, and in some cases to make predictions about the cognates of "orphan" histidine kinase or response ...