Title : Crystal structure of human
RANKL complexed with its decoy receptor
osteoprotegerin
Abstract :
- Receptor activator of NF-κB ligand ( RANKL ), its signaling receptor RANK , and its decoy receptor osteoprotegerin ( OPG ) constitute a molecular triad that is critical in regulating bone remodeling, and also plays multiple roles in the immune system
- OPG binds RANKL directly to block its interaction with RANK
- In this article, we report the 2.7-Å crystal structure of human RANKL trimer in complex with the N-terminal fragment of human OPG containing four cysteine-rich TNFR homologous domains ( OPG-CRD)
- The structure shows that RANKL trimer uses three equivalent grooves between two neighboring monomers to interact with three OPG-CRD monomers symmetrically
- A loop from the CRD3 domain of OPG-CRD inserts into the shallow groove of RANKL , providing the major binding determinant that is further confirmed by affinity measurement and osteoclast differentiation assay
- These results, together with a previously reported mouse RANKL/RANK complex structure, reveal that OPG exerts its decoy receptor function by directly blocking the accessibilities of important interacting residues of RANKL for RANK recognition
- Structural comparison with TRAIL / death receptor 5 complex also reveals structural basis for the cross-reactivity of OPG to TRAIL
Output (sent_index, trigger,
protein,
sugar,
site):
Output(Part-Of) (sent_index,
protein,
site):
- 3. N-terminal, fragment
- 3. OPG, domains
- 3. OPG, fragment
- 5. OPG, domain
- 6. RANKL, residues
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):