The Solution Structure of BMPR-IA Reveals a Local Disorder-to-Order Transition upon BMP-2 Binding

Biochemistry, 2008, 47, 11930-9 published on 21.10.2007
Biochemistry, online article
The structure of the extracellular domain of BMP receptor IA was determined in solution by NMR spectroscopy and compared to its structure when bound to its ligand BMP-2. While most parts of the secondary structure are highly conserved between the bound and unbound forms, large conformational rearrangements can be observed in the b4b5 loop of BMPR-IA, which is in contact with BMP-2 and harbors the main binding determinants for the BMPR-IA-BMP-2 interaction. In its unbound form, helix R1 in BMPR-IA, which is in the center of the binding epitope for BMP-2, is missing. Since BMP-2 also shows conformational changes in the type I receptor epitope upon binding to BMPR-IA, both binding partners pass through an induced fit mechanism to adapt their binding interfaces to a given interaction surface. The inherent flexibility of both partners possibly explains the promiscuous ligand-receptor interaction observed in the BMP protein superfamily.

TU München
Helmholtz München
MPI of Neurobiology
MPI of Biochemistry