X-ray structure of full-length annexin 1 and implications for membrane aggregation.Rosengarth, A., Gerke, V., Luecke, H.
(2001) J.Mol.Biol. 306: 489-498
- PubMed: 11178908
- DOI: 10.1006/jmbi.2000.4423
- PubMed Abstract:
- Crystallization and Preliminary X-ray Analysis of Full-length Annexin I Comprising the Core and N-terminal Domain.
Rosengarth, A.,Luecke, H.
(2000) Acta Crystallogr.,Sect.D 56: 1459
Annexins comprise a multigene family of Ca2+ and phospholipid- binding proteins. They consist of a conserved C-terminal or core domain that confers Ca2+-dependent phospholipid binding and an N-terminal domain that is variable in sequence and length a ...
Annexins comprise a multigene family of Ca2+ and phospholipid- binding proteins. They consist of a conserved C-terminal or core domain that confers Ca2+-dependent phospholipid binding and an N-terminal domain that is variable in sequence and length and responsible for the specific properties of each annexin. Crystal structures of various annexin core domains have revealed a high degree of similarity. From these and other studies it is evident that the core domain harbors the calcium-binding sites that interact with the phospholipid headgroups. However, no structure has been reported of an annexin with a complete N-terminal domain. We have now solved the crystal structure of such a full-length annexin, annexin 1. Annexin 1 is active in membrane aggregation and its refined 1.8 A structure shows an alpha-helical N-terminal domain connected to the core domain by a flexible linker. It is surprising that the two alpha-helices present in the N-terminal domain of 41 residues interact intimately with the core domain, with the amphipathic helix 2-12 of the N-terminal domain replacing helix D of repeat III of the core. In turn, helix D is unwound into a flap now partially covering the N-terminal helix. Implications for membrane aggregation will be discussed and a model of aggregation based on the structure will be presented.
Department of Molecular Biology and Biochemistry and UCI Program in Macromolecular Structure, University of California, 3205 Biological Sciences II, Irvine, CA, 92697-3900, USA.