Modeling the primary hormone-binding site of RXFP1 and RXFP2.
The primary binding sites of the relaxin and insulin-like peptide 3 (INSL3) receptors, RXFP1 and RXFP2, are found within the leucine-rich repeats (LRRs) of the ectodomains. Specific B-chain residues in the peptides interact with residues in the inner beta-sheets of the LRRs of the receptors. Relaxin binds to RXFP2 with high affinity, although INSL3 has a very poor affinity for RXFP1. In this paper we present evidence that relaxin binds to the LRRs of RXFP2 in a manner similar to INSL3 binding to its receptor. Additionally, we introduce a model of this binding interaction and compare it to an alternate model for relaxin-RXFP1 binding.
Scott
Daniel J
DJ
Department of Biochemistry and Molecular Biology, Howard Florey Institute, University of Melbourne, Parkville, Victoria, Australia.
Tregear
Geoffrey W
GW
Bathgate
Ross A D
RA
D001665:Binding Sites; D006801:Humans; D008958:Models, Molecular; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D043562:Receptors, G-Protein-Coupled / Q000737:chemistry* / Q000378:metabolism*; D018000:Receptors, Peptide / Q000737:chemistry* / Q000378:metabolism*; D012065:Relaxin / Q000737:chemistry / Q000378:metabolism
C417543:RXFP1 protein, human; C472867:RXFP2 protein, human; D043562:Receptors, G-Protein-Coupled; D018000:Receptors, Peptide; D012065:Relaxin