The family of myotubularin (MTM) phosphoinositide phosphatases includes catalytically inactive members, or pseudophosphatases, which contain inactivating substitutions in the phosphatase domain []. Myotubularin-related protein 11 (MTMR11) is a probable pseudophosphatase. It contains a Glu residue instead of a conserved Cys residue in the dsPTPase catalytic loop which renders it catalytically inactive as a phosphatase.
This domain is found at the C terminus of myotubularin-related (MTMR) proteins MTMR10, MTMR11 and MTMR12; and is typically between 115 and 138 amino acids in length. Myotubularin-related protein 12 (also known as the phosphatidylinositol-3 phosphate 3-phosphatase adapter subunit, 3-PAP) is a catalytically inactive member of the myotubularin gene family, which plays a role as an adapter for the phosphatidylinositol 3-phosphate-3-phosphatase myotubularin []. MTMR10 and MTMR11 are also catalytically inactive.
