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]

• Lactose permease
• Beta-galactoside permease

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.

• Amino acid permease

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.

• Permeases at the U.S. National Library of Medicine Medical Subject Headings (MeSH)