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Enzyme induction is a process in which a molecule (e.g., a drug) induces (i.e., initiates or enhances) the expression of an enzyme. The induction of heat shock proteins in the fruit fly Drosophila melanogaster. The Lac operon is an interesting example of how gene expression can be regulated.
In prokaryotes, the term corepressor is used to denote the activating ligand of a repressor protein. For example, the E. coli tryptophan repressor (TrpR) is only able to bind to DNA and repress transcription of the trp operon when its corepressor tryptophan is bound to it.
The Gal4 transcription factor is a positive regulator of gene expression of galactose-induced genes. [1] This protein represents a large fungal family of transcription factors, Gal4 family, which includes over 50 members in the yeast Saccharomyces cerevisiae e.g. Oaf1, Pip2, Pdr1, Pdr3, Leu3.
This includes the functions of histone remodeling enzymes, transcription factors, enhancers and repressors, and many other complexes Productive elongation of the RNA transcript. Once polymerase is bound to a promoter, it requires another set of factors to allow it to escape the promoter complex and begin successfully transcribing RNA.
The L-arabinose operon houses genes coding for arabinose-digesting enzymes. These function to break down arabinose as an alternative source for energy when glucose is low or absent. [ 4 ] The operon consists of a regulatory repressor gene (araC), three control sites (ara02, ara01, araI1, and araI2), two promoters (Parac/ParaBAD) and three ...
Tryptophan synthase or tryptophan synthetase is an enzyme (EC 4.2.1.20) that catalyzes the final two steps in the biosynthesis of tryptophan. [1] [2] It is commonly found in Eubacteria, [3] Archaebacteria, [4] Protista, [5] Fungi, [6] and Plantae. [7] However, it is absent from Animalia. [8] It is typically found as an α2β2 tetramer.
Recent studies [citation needed] have shown that the manipulation of pectinesterase expression can influence numerous physiological processes. In plants, pectinesterase plays a role in the modulation of cell wall mechanical stability during fruit ripening, cell wall extension during pollen germination and pollen tube growth, abscission, stem elongation, tuber yield and root development.
Photosystem II (of cyanobacteria and green plants) is composed of around 20 subunits (depending on the organism) as well as other accessory, light-harvesting proteins. Each photosystem II contains at least 99 cofactors: 35 chlorophyll a, 12 beta-carotene , two pheophytin , two plastoquinone , two heme , one bicarbonate, 20 lipids, the Mn