9II3: 2:1 Complex of mGlu3 and beta-arrestin1

Cryo-EM Structure of the 2:1 Complex of mGlu3 and beta-arrestin1. Determined by electron microscopy at 3.9 Å resolution. Released 5 Mar 2025.

Method: Electron microscopy
Resolution: 3.9 Å
Organisms: Homo sapiens, Mus musculus
Chains: 4
Atoms: 16,488
Mol. weight: 274.57 kDa
Ligands: GLU, CLR
Released: 5 Mar 2025

Explore 9II3 in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9II3 contains 70 α-helices and 106 β-strands across 4 chains. Residue ranges use author residue numbering, as in the PDB file, from PDBe. To see them in 3D, choose the Cartoon representation with Secondary structure coloring: helices, sheets and coils get different colors.

Chain A: 10 helices, 28 β-strands

Element	Residues	Length	Sheet
β-strand	6	1	10
β-strand	9-11	3	11
β-strand	19-22	4	11
β-strand	26-28	3	12
β-strand	29	1	13
β-strand	34	1	13
α-helix	35-36	2
β-strand	37-42	6	11
β-strand	52-63	12	9
α-helix	66-71	6
β-strand	75-85	11	9
α-helix	99-108	10
β-strand	112-117	6	11
α-helix	119-120	2
α-helix	123-125	3
β-strand	127-129	3	9
α-helix	130-131	2
α-helix	139-140	2
β-strand	141-151	11	9
β-strand	164-168	5	9
β-strand	169-171	3	12
α-helix	181-182	2
β-strand	183-187	5	14
β-strand	190	1	15
β-strand	195	1	15
β-strand	197-202	6	14
β-strand	207-208	2	16
β-strand	214-222	9	14
β-strand	231-241	11	17
β-strand	249-258	10	17
β-strand	267-274	8	14
β-strand	288-290	3	9
α-helix	291-292	2
β-strand	300	1	9
α-helix	301-302	2
β-strand	317-328	12	17
β-strand	342-349	8	17
β-strand	350-351	2	16

Chain B: 28 helices, 28 β-strands

Element	Residues	Length	Sheet
β-strand	32-35	4	23
β-strand	39-45	7	23
β-strand	48	1	24
β-strand	60	1	24
α-helix	64-81	18
β-strand	91-97	7	23
α-helix	102-120	19
β-strand	134	1	3
β-strand	142-147	6	23
α-helix	151-162	12
β-strand	168-170	3	23
α-helix	176-179	4
β-strand	187-189	3	23
α-helix	194-207	14
β-strand	212-217	6	25
α-helix	221-236	16
β-strand	240-246	7	25
α-helix	255-264	10
β-strand	271-275	5	25
α-helix	278-290	13
β-strand	296-298	3	25
α-helix	308-310	3
β-strand	321-325	5	25
α-helix	331-338	8
α-helix	351-358	8
β-strand	362	1	26
β-strand	372	1	26
α-helix	390-411	22
α-helix	420-423	4
α-helix	427-429	3
α-helix	430-435	6
β-strand	466-470	5	25
β-strand	481-486	6	25
β-strand	490	1	25
α-helix	494-496	3
β-strand	519-521	3	27
β-strand	530-532	3	27
β-strand	538-542	5	28
β-strand	545-548	4	28
β-strand	553-555	3	29
β-strand	562-564	3	29
α-helix	565-566	2
β-strand	567-568	2	30
α-helix	578-600	23
α-helix	605-609	5
α-helix	612-632	21
α-helix	638-670	33
α-helix	684-709	26
β-strand	714-717	4	30
β-strand	726-730	5	30
α-helix	734-757	24
α-helix	767-792	26
α-helix	796-814	19
α-helix	815-819	5
α-helix	820-823	4
α-helix	824-828	5

Chain R: 30 helices, 28 β-strands

Element	Residues	Length	Sheet
β-strand	32-35	4	1
β-strand	39-45	7	1
β-strand	48	1	2
α-helix	59	1
β-strand	60	1	2
α-helix	61	1
α-helix	65-81	17
β-strand	91-97	7	1
α-helix	102-113	12
α-helix	116-120	5
β-strand	130	1	3
β-strand	142-147	6	1
α-helix	151-162	12
β-strand	168-170	3	1
α-helix	176-179	4
β-strand	187-189	3	1
α-helix	194-207	14
β-strand	214-217	4	4
α-helix	221-236	16
β-strand	246	1	4
α-helix	255-264	10
β-strand	272-275	4	4
α-helix	278-290	13
β-strand	297-299	3	4
α-helix	308-310	3
β-strand	321-325	5	4
α-helix	331-337	7
α-helix	351-358	8
α-helix	390-411	22
α-helix	427-429	3
α-helix	430-435	6
β-strand	461	1	1
β-strand	466-471	6	4
β-strand	480-486	7	4
β-strand	492	1	4
α-helix	494-496	3
β-strand	518-521	4	5
β-strand	530-533	4	5
β-strand	538-542	5	6
β-strand	545-548	4	6
β-strand	553-555	3	7
β-strand	562-564	3	7
α-helix	565-567	3
α-helix	578-600	23
α-helix	605-632	28
α-helix	638-671	34
α-helix	684-688	5
α-helix	689-709	21
β-strand	714-718	5	8
β-strand	726-730	5	8
α-helix	734-757	24
α-helix	763-791	29
α-helix	797-814	18
α-helix	815-819	5
α-helix	820-823	4
α-helix	824-828	5
β-strand	836	1	9
β-strand	862	1	10

Chain S: 2 helices, 22 β-strands

Element	Residues	Length	Sheet
β-strand	5-6	2	18
β-strand	20-26	7	18
β-strand	34-39	6	19
β-strand	46-50	5	19
β-strand	54-55	2	19
α-helix	56	1
β-strand	67-68	2	18
β-strand	71-76	6	18
β-strand	86-87	2	19
β-strand	90-91	2	19
β-strand	103	1	19
β-strand	1008-1010	3	20
β-strand	1014	1	21
β-strand	1018-1026	9	20
β-strand	1035-1042	8	22
β-strand	1048-1055	8	22
β-strand	1060-1063	4	22
β-strand	1071-1076	6	20
β-strand	1081-1089	9	20
α-helix	1090-1092	3
β-strand	1095-1103	9	22
β-strand	1110-1113	4	22
β-strand	1117-1119	3	22
β-strand	1120	1	21

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Metabotropic glutamate receptor 3	B, R	protein	879	Homo sapiens	Q14832 (AlphaFold model)
Beta-arrestin-1	A	protein	418	Homo sapiens	P49407 (AlphaFold model)
scFv30	S	protein	251	Mus musculus

Sequence of entity 1 (B, R), FASTA

>9II3_1 Metabotropic glutamate receptor 3 (chains B, R)
MKMLTRLQVLTLALFSKGFLLSLGDHNFLRREIKIEGDLVLGGLFPINEKGTGTEECGRI
NEDRGIQRLEAMLFAIDEINKDDYLLPGVKLGVHILDTCSRDTYALEQSLEFVRASLTKV
DEAEYMCPDGSYAIQENIPLLIAGVIGGSYSSVSIQVANLLRLFQIPQISYASTSAKLSD
KSRYDYFARTVPPDFYQAKAMAEILRFFNWTYVSTVASEGDYGETGIEAFEQEARLRNIC
IATAEKVGRSNIRKSYDSVIRELLQKPNARVVVLFMRSDDSRELIAAASRANASFTWVAS
DGWGAQESIIKGSEHVAYGAITLELASQPVRQFDRYFQSLNPYNNHRNPWFRDFWEQKFQ
CSLQNKRNHRRVCDKHLAIDSSNYEQESKIMFVVNAVYAMAHALHKMQRTLCPNTTKLCD
AMKILDGKKLYKDYLLKINFTAPFNPNKDADSIVKFDTFGDGMGRYNVFNFQNVGGKYSY
LKVGHWAETLSLDVNSIHWSRNSVPTSQCSDPCAPNEMKNMQPGDVCCWICIPCEPYEYL
ADEFTCMDCGSGQWPTADLTGCYDLPEDYIRWEDAWAIGPVTIACLGFMCTCMVVTVFIK
HNNTPLVKASGRELCYILLFGVGLSYCMTFFFIAKPSPVICALRRLGLGSSFAICYSALL
TKTNCIARIFDGVKNGAQRPKFISPSSQVFICLGLILVQIVMVSVWLILEAPGTRRYTLA
EKRETVILKCNVKDSSMLISLTYDVILVILCTVYAFKTRKCPENFNEAKFIGFTMYTTCI
IWLAFLPIFYVTSSDYRVQTTTMCISVSLSGFVVLGCLFAPKVHIILFQPQKNVVTHRLH
LNRFSVSGTGTTYSQSSASTYVPTVCNGREVLDSTTSSL

Sequence of entity 2 (A), FASTA

>9II3_2 Beta-arrestin-1 (chains A)
MGDKGTRVFKKASPNGKLTVYLGKRDFVDHIDLVDPVDGVVLVDPEYLKERRVYVTLTVA
FRYGREDLDVLGLTFRKDLFVANVQSFPPAPEDKKPLTRLQERLIKKLGEHAYPFTFEIP
PNLPSSVTLQPGPEDTGKALGVDYEVKAFVAENLEEKIHKRNSVRLVIEKVQYAPERPGP
QPTAETTRQFLMSDKPLHLEASLDKEIYYHGEPISVNVHVTNNTNKTVKKIKISVRQYAD
IVLFNTAQYKVPVAMEEADDTVAPSSTFSKVYTLTPFLANNREKRGLALDGKLKHEDTNL
ASSTLLREGANREILGIIVSYKVKVKLVVSRGGLLGDLASSDVAVELPFTLMHPKPKEEP
PHREVPENETPVDTNLIELDTNDDDIVFEDFARQRLKGMKDDKEEEEDGTGSPQLNNR

Sequence of entity 3 (S), FASTA

>9II3_3 scFv30 (chains S)
SDIQMTQSPSSLSASVGDRVTITCRASQSVSSAVAWYQQKPGKAPKLLIYSASSLYSGVP
SRFSGSRSGTDFTLTISSLQPEDFATYYCQQYKYVPVTFGQGTKVEIKGTTAASGSSGGS
SSGAEVQLVESGGGLVQPGGSLRLSCAASGFNVYSSSIHWVRQAPGKGLEWVASISSYYG
YTYYADSVKGRFTISADTSKNTAYLQMNSLRAEDTAVYYCARSRQFWYSGLDYWGQGTLV
TVSSAHHHHHH

Ligands and cofactors

ID	Name	Formula	Copies
GLU	Glutamic acid	C5 H9 N O4	2
CLR	Cholesterol	C27 H46 O	2

Primary citation

Molecular basis of beta-arrestin coupling to the metabotropic glutamate receptor mGlu3. Wen, T., Du, M., Lu, Y. et al. Nat Chem Biol (2025) 21:1262-1269. DOI 10.1038/s41589-025-01858-8 · PubMed

Other PDB entries of the same protein (UniProt Q14832 (AlphaFold model), which also has an AlphaFold model), best resolution first:

3SM9 2.26 Å, Crystal Structure of Metabotropic glutamate receptor 3 precursor in presence of LY341495…
4XAR 2.26 Å, mGluR2 ECD and mGluR3 ECD complex with ligands
8JCU 2.8 Å, Cryo-EM structure of mGlu2-mGlu3 heterodimer in presence of LY341495 (dimerization mode I)
8JD2 2.8 Å, Cryo-EM structure of G protein-free mGlu2-mGlu3 heterodimer in Acc state
6B7H 2.82 Å, Structure of mGluR3 with an agonist
5CNM 2.84 Å, mGluR3 complexed with glutamate analog
8JCY 2.9 Å, Cryo-EM structure of mGlu2-mGlu3 heterodimer in presence of LY341495, NAM563, and…
8JCW 3.0 Å, Cryo-EM structure of mGlu2-mGlu3 heterodimer in presence of LY341495 and NAM563…
8JCX 3.0 Å, Cryo-EM structure of mGlu2-mGlu3 heterodimer in presence of LY341495 and NAM563…
8JCZ 3.0 Å, Cryo-EM structure of mGlu2-mGlu3 heterodimer in presence of LY341495, NAM563, and…
5CNK 3.15 Å, mglur3 with glutamate
8JD0 3.3 Å, Cryo-EM structure of mGlu2-mGlu3 heterodimer in presence of NAM563

Browse structure collections

About this viewer

MolViewer shows 9II3 directly in your browser with nothing to install. Switch between cartoon, ball-and-stick, spacefill and surface views, color by chain, secondary structure or B-factor, measure distances, angles and dihedrals, and share or embed the view.