Download MendeleySolution structure of the constant region of nuclear envelope protein LAP2 reveals two LEM-domain structures: one binds BAF and the other binds DNA.
Cai, M., Huang, Y., Ghirlando, R., Wilson, K.L., Craigie, R., Clore, G.M.(2001) EMBO J 20: 4399-4407
- PubMed: 11500367
- DOI: https://doi.org/10.1093/emboj/20.16.4399
- Primary Citation of Related Structures:
1GJJ - PubMed Abstract:
The nuclear envelope proteins LAP2, emerin and MAN1 share a conserved approximately 40-residue 'LEM' motif. Loss of emerin causes Emery-Dreifuss muscular dystrophy. We have solved the solution NMR structure of the constant region of human LAP2 (residues 1-168). Human LAP2(1-168) has two structurally independent, non-interacting domains located at residues 1-50 ('LAP2-N') and residues 111-152 (LEM-domain), connected by an approximately 60-residue flexible linker. The two domains are structurally homologous, comprising a helical turn followed by two helices connected by an 11-12-residue loop. This motif is shared by subdomains of T4 endonuclease VII and transcription factor rho, despite negligible (< or =15%) sequence identity. NMR chemical shift mapping demonstrated that the LEM-domain binds BAF (barrier-to-autointegration factor), whereas LAP2-N binds DNA. Both binding surfaces comprise helix 1, the N-terminus of helix 2 and the inter-helical loop. Binding selectivity is determined by the nature of the surface residues in these binding sites, which are predominantly positively charged for LAP2-N and hydrophobic for the LEM-domain. Thus, LEM and LEM-like motifs form a common structure that evolution has customized for binding to BAF or DNA.
Organizational Affiliation:
Laboratory of Chemical Physics, Building 5, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0510, USA.
