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.

Although lactose permease (LacY) represents one of the most extensively characterized transport proteins, it is not known exactly how this protein inserts into the membrane. Controversial results were obtained for LacY from different in vivo and in vitro techniques.

Oct 7, 2024 · Lactose permease is a crucial protein responsible for transporting lactose across the cellular membrane in bacteria. This protein’s importance extends beyond just nutrient uptake; it offers significant insights into the mechanics of membrane transport proteins.

Jun 1, 2005 · Lactose permease of Escherichia coli (LacY), the second structural gene in the lac operon [6], is encoded by lacY and is the first gene encoding a membrane transport protein to be cloned into a recombinant plasmid, overexpressed [7] and sequenced [8].

Feb 23, 2018 · Lactose permease of Escherichia coli (LacY), a galactoside/H+ symporter, is a paradigm for cation-coupled membrane-transport proteins. This integral membrane protein is composed of two pseudo-symmetrical six-helix bundles surrounding an …

Transport involves substrate-specific membrane proteins that catalyze equilibration and/or uphill translocation of solute across a membrane. These proteins are called a variety of interchangeable names—symporters, cotransporters, transporters, carriers, or permeases.

Jun 22, 2009 · The putative transport process shown is composed of eight steps: (I) Lactose binds to ground state LacY, in which a Glutamate E 1 is protonated. (II) The periplasmic side of LacY closes, induced by the movement of the lactose to the binding pocket.

Jun 1, 2004 · This article describes the configuration and implied transport mechanism of the bacterial lactose transporter and compares its structure and function with those of other transporters and those of ion channels.

Jun 15, 2023 · Lactose Permease or galactoside permease (PDB entry 1pv7) is a transmembrane protein that facilitates the passage of lactose across the phospholipid bi-layer of the cell membrane. The transport mechanism used is an active co-transport that uses the inwardly directed H+ electrochemical gradient as its driving force.

Aug 1, 2003 · We propose a possible mechanism for lactose/proton symport (co-transport) consistent with both the structure and a large body of experimental data. Membrane transport proteins that transduce free energy stored in electrochemical ion gradients into a concentration gradient are a major class of membrane proteins.