Table 1.

Ectodomains and ligands of the LGR family.

Name	Short annotated name	Ligand	No of LRRs	Residues per repeat	Ligand affinitya	PDB
Type A
LGR1	FSHr	Follicle-stimulating hormone	9	21–25	0.03–3 nMb	1XWD, 4AY9, 4MQW
LGR2	LH/CGr	Lutropin or choriogonadotropic hormone	6	22–31	0.3–0.5 nMc
LGR3	TSHr	Thyrotropin (thyroid-stimulating hormone)	7	20–31	0.25 nMd	3XWT,3GO4
Type B
LGR4	LGR4	Rspondin1–4	17	20–25	56 nMe	4KT1, 4QXE, 4QXF
LGR5	LGR5	Rspondin1–4	17	21–26	3 nMf	4BSR, 4BSS, 4BST
						4BSU, 4KNG
LGR6	LGR6	Rspondin1–4	17	21–25	0.5–7 nMg
Type C
LGR7	RXFP1	H2 relaxin	10	24–25	9.2–9.8h	2JM4 (LDLa module)
LGR8	RXFP2	INSL3, H2 relaxin	10	24	9.3–9.7, 8.5–9.0h	2M96 (LDLa module)

^aReported K_d, unless noted.

^bSimoni et al. (31).

^cAscoli et al. (32).

^dHarfst et al. (33).

^eWang et al. (34).

^fde Lau et al. (3).

^gIC₅₀ (35).

^hpK_d or pK_i (36).