The LEM (LAP2, emerin, MAN1) domain is a globular module of approximately 40amino acids, which is mostly found in the nucleoplasmic portions of metazoaninner nuclear membrane proteins. The LEM domain has been shown to mediatebinding to BAF (barrier-to-autointegration factor) and BAF-DNA complexes. BAFdimers bind to double-stranded DNA non-specifically and thereby bridge DNAmolecules to form a large, discrete nucleoprotein complex [, ].The resolution of the solution structure of the LEM domain reveals that it iscomposed of a three-residue N-terminal helical turn and two large parallelalpha helices interacting through a set of conserved hydrophobic amino acids. The two helices, which are connected by a long loop are oriented at an angle of ~45 degree [, ].Proteins known to contain a LEM domain include:Vertebrate inner nuclear membrane protein MAN1. Vertebrate lamina-associated polypeptide 2 (LAP2) or thymopoietin. Mammalian emerin (EMD). In human, defects in EMD are a cause of X-linked Emery-Dreifuss muscular dystrophy (X-EDMD), an X-linked disorder, characterised by early contractures, muscle wasting and weakness and cardiomyopathy.Xenopus laevis Smad1 antagonistic effector (SANE).Drosophila melanogaster otefin (OTE).Caenorhabditis elegans W01G7.5 protein.
