[2] The GUK domain that they have is structurally very similar to that of the guanylate kinases, however it is known to be catalytically inactive as the P-Loop which binds ATP is absent.
The number of PDZ domain copies varies between different members of the MAGUK family.
The PDZ domains found within each family member often have different binding partners, due to variations in their amino acid compositions.
One of the most well known features is that it can form an intramolecular bond with the GUK domain, creating what is known as a GUK-SH3 'closed' state.
Humans genes encoding members of the MAGUK protein superfamily include: