Permease

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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]

Contents

The permease binding is the first step of translocation. LacY protein from Escherichia coli is an example of a permease. [2]

See also

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.

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<span class="mw-page-title-main">Lactose permease</span> Membrane protein

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.

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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.

References

  1. "Substrate Transport in Lactose Permease".
  2. J., Ninfa, Alexander; P., Ballou, David (2004). Fundamental laboratory approaches for biochemistry and biotechnology. Wiley. ISBN   1891786008. OCLC   633862582.{{cite book}}: CS1 maint: multiple names: authors list (link)