Maltose permease is a protein found in the cell membranes of certain bacteria, such as Escherichia coli. It functions as a transporter, facilitating the uptake of maltose, a sugar composed of two glucose molecules. This process is essential for bacteria that rely on maltose as a source of energy. The protein operates through a mechanism known as active transport, which requires energy to move maltose against its concentration gradient. By efficiently transporting maltose into the cell, maltose permease plays a crucial role in the metabolism of bacteria, enabling them to thrive in various environments where maltose is present.