Class 1 and Class 2 Glucose transporters (GLUTs) of the Major Facilitator Superfamily
This subfamily includes Class 1 and Class 2 glucose transporters (GLUTs) including Solute carrier family 2, facilitated glucose transporter member 1 (SLC2A1, also called glucose transporter type 1 or GLUT1), SLC2A2-5 (GLUT2-5), SLC2A7 (GLUT7), SLC2A9 (GLUT9), SLC2A11 (GLUT11), SLC2A14 (GLUT14), and similar proteins. GLUTs are a family of proteins that facilitate the transport of hexoses such as glucose and fructose. There are fourteen GLUTs found in humans; they display different substrate specificities and tissue expression. They have been categorized into three classes based on sequence similarity: Class 1 (GLUTs 1-4, 14); Class 2 (GLUTs 5, 7, 9, and 11); and Class 3 (GLUTs 6, 8, 10, 12, and HMIT). GLUTs 1-5 are the most thoroughly studied and are well-established as glucose and/or fructose transporters in various tissues and cell types. GLUT proteins are comprised of about 500 amino acid residues, possess a single N-linked oligosaccharide, and have 12 transmembrane segments. They belong to the Glucose transporter -like (GLUT-like) family of the Major Facilitator Superfamily (MFS) of membrane transport proteins. MFS proteins are thought to function through a single substrate binding site, alternating-access mechanism involving a rocker-switch type of movement.
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