The permeases are membrane transport proteins, a class of multipass transmembrane proteins that allow the diffusion of a specific molecule in or out of the cell in the direction of a concentration gradient, a form of facilitated diffusion. [1]
The permease binding is the first step of translocation. LacY protein from Escherichia coli is an example of a permease. [2]
It was originally discovered in the 1930s by Joy Adames. It is a transporter protein that helps in various aspects of cellular life including DNA replication, translation of RNA, and diffusion.
A permease (porter) is a protein or protein complex that catalyzes a vectorial reaction, irrespective of whether or not it also catalyzes a chemical or electron transfer reaction that drives the vectorial process.
Facilitated diffusion is the process of spontaneous passive transport of molecules or ions across a biological membrane via specific transmembrane integral proteins. Being passive, facilitated transport does not directly require chemical energy from ATP hydrolysis in the transport step itself; rather, molecules and ions move down their concentration gradient according to the principles of diffusion.
β-Galactosidase is a glycoside hydrolase enzyme that catalyzes hydrolysis of terminal non-reducing β-D-galactose residues in β-D-galactosides.
The lactose 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 enteric bacteria, the lac operon allows for the effective digestion of lactose when glucose is not available through the activity of β-galactosidase. 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.
PEP group translocation, also known as the phosphotransferase system or PTS, is a distinct method used by bacteria for sugar uptake where the source of energy is from phosphoenolpyruvate (PEP). It is known to be a multicomponent system that always involves enzymes of the plasma membrane and those in the cytoplasm.
Isopropyl β-d-1-thiogalactopyranoside (IPTG) is a molecular biology reagent. This compound is a molecular mimic of allolactose, a lactose metabolite that triggers transcription of the lac operon, and it is therefore used to induce protein expression where the gene is under the control of the lac operator.
Galactoside permease is a protein coded by the lacY gene of the lac operon, and is found bound to the membrane of a cell for the purpose of binding galactoside molecules that have been solubilized. The protein is part of a system whose main function is to catalyze the accumulation and transport of lactose and other beta-galactosides across the permeable barrier of a membrane.
Phosphatidylethanolamine (PE) is a class of phospholipids found in biological membranes. They are synthesized by the addition of cytidine diphosphate-ethanolamine to diglycerides, releasing cytidine monophosphate. S-Adenosyl methionine can subsequently methylate the amine of phosphatidylethanolamines to yield phosphatidylcholines.
In enzymology, a manganese-transporting ATPase (EC 3.6.3.35) is an enzyme that catalyzes the chemical reaction
The ABC-type oligopeptide transporter (EC 7.4.2.6) or oligopeptide permease is an enzyme that catalyzes the chemical reaction
In enzymology, an oligosaccharide-transporting ATPase (EC 3.6.3.18) is an enzyme that catalyzes the chemical reaction
In enzymology, a protein-Npi-phosphohistidine-sugar phosphotransferase is an enzyme that catalyzes the chemical reaction
Lactose permease is a membrane protein which is a member of the major facilitator superfamily. Lactose permease can be classified as a symporter, which uses the proton gradient towards the cell to transport β-galactosides such as lactose in the same direction into the cell.
Howard Ronald Kaback was an American biochemist, known for Kabackosomes, the cell-free membrane transport vesicles. He was the brother of Michael M. Kaback, pediatrician and human geneticist, who developed a screening program to detect and prevent Tay–Sachs disease, a rare and fatal genetic disorder most common in Ashkenazi Jews.
Proteins currently known to belong to the Ni2+-Co2+ Transporter (NiCoT) family (TC# 2.A.52) can be found in organisms ranging from Gram-negative and Gram-positive bacteria to archaea and some eukaryotes. Members of this family catalyze uptake of Ni2+ and/or Co2+ in a proton motive force-dependent process.
The Hydroxy/Aromatic Amino Acid Permease (HAAAP) Family is a member of the large Amino Acid-Polyamine-OrganoCation (APC) Superfamily of secondary carrier proteins. Members of the HAAAP family all function in amino acid uptake. Homologues are present in many Gram-negative and Gram-positive bacteria, with at least one member classified from archaea .
The Pho1 phosphate permease family is a family of phosphate transporters belonging to the ion transporter (IT) superfamily. Representative members of the Pho1 family include the putative phosphate transporter PHO1 of Arabidopsis thaliana, and the xenotropic and polytropic murine-leukemia virus receptor Xpr1 of Culex pipiens.
The inorganic phosphate transporter (PiT) family is a group of carrier proteins derived from Gram-negative and Gram-positive bacteria, archaea, and eukaryotes.
The phosphotransferases system (PTS-GFL) superfamily is a superfamily of phosphotransferase enzymes that facilitate the transport of glucose, glucitol (G), fructose (F) and lactose (L). Classification has been established through phylogenic analysis and bioinformatics.
The PTS Lactose-N,N’-Diacetylchitobiose (Lac) Family includes several sequenced lactose porters of Gram-positive bacteria, as well as the Escherichia coli and Borrelia burgdorferi N,N'-diacetylchitobiose (Chb) porters. It is part of the PTS-GFL superfamily. The former can transport aromatic β-glucosides and cellobiose, as well as Chb. However, only Chb induces expression of the chb operon.
The Glycoside-Pentoside-Hexuronide (GPH):Cation Symporter Family is part of the major facilitator superfamily and catalyzes uptake of sugars (mostly, but not exclusively, glycosides) in symport with a monovalent cation (H+ or Na+). The various members of the family have been reported to use Na+, H+ or Li, Na+ or Li+, or all three cations as the symported cation.
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