Homotetramer

A homotetramer is a protein complex made up of four identical subunits which are associated but not covalently bound. A heterotetramer is a 4-subunit complex where one or more subunits differ.

Examples of homotetramers include: enzymes like beta-glucuronidase (pictured); export factors such as SecB from Escherichia coli and magnesium ion transporters such as CorA.