20YC: GPR174-Gi complex

Cryo-EM structure of GPR174-Gi complex. Determined by electron microscopy at 3.4 Å resolution. Released 15 Apr 2026.

Method: Electron microscopy
Resolution: 3.4 Å
Organism: Homo sapiens
Chains: 4
Atoms: 7,082
Mol. weight: 124.06 kDa
Released: 15 Apr 2026

Explore 20YC in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

20YC contains 34 α-helices and 36 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: 11 helices, 8 β-strands

Element	Residues	Length	Sheet
α-helix	9-31	23
β-strand	34-38	5	1
α-helix	46-54	9
β-strand	185-190	6	1
β-strand	195-200	6	1
α-helix	208-210	3
α-helix	212-215	4
β-strand	220-226	7	1
α-helix	227-231	5
β-strand	233	1	2
β-strand	241	1	2
α-helix	242-254	13
α-helix	257-259	3
β-strand	263-269	7	1
α-helix	271-280	10
α-helix	283-285	3
α-helix	296-309	14
β-strand	319-322	4	1
α-helix	330-351	22

Chain B: 5 helices, 28 β-strands

Element	Residues	Length	Sheet
α-helix	4-24	21
α-helix	30-33	4
α-helix	38-39	2
β-strand	47-51	5	3
β-strand	58-63	6	4
β-strand	69-74	6	4
β-strand	78-83	6	4
β-strand	88-94	7	4
α-helix	95	1
β-strand	102-105	4	5
β-strand	111-115	5	5
β-strand	120-125	6	5
β-strand	134-140	7	5
β-strand	146-151	6	6
β-strand	156-161	6	6
β-strand	165-170	6	6
β-strand	175-181	7	6
β-strand	187-192	6	7
β-strand	198-203	6	7
β-strand	207-212	6	7
β-strand	218-222	5	7
β-strand	229-234	6	8
β-strand	240-245	6	8
β-strand	250-254	5	8
β-strand	259-264	6	8
α-helix	272	1
β-strand	273-278	6	9
β-strand	284-289	6	9
β-strand	294-298	5	9
β-strand	304-308	5	9
β-strand	317-320	4	3
β-strand	327-330	4	3
β-strand	336-339	4	3

Chain C: 3 helices, 0 β-strands

Element	Residues	Length
α-helix	10-21	12
α-helix	30-43	14
α-helix	45-47	3

Chain R: 15 helices, 0 β-strands

Element	Residues	Length
α-helix	21-50	30
α-helix	56-70	15
α-helix	72-81	10
α-helix	88-121	34
α-helix	134-149	16
α-helix	151-156	6
α-helix	162-164	3
α-helix	169-171	3
α-helix	179-190	12
α-helix	191-195	5
α-helix	196-214	19
α-helix	218-221	4
α-helix	223-257	35
α-helix	264-292	29
α-helix	297-302	6

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Guanine nucleotide-binding protein G(i) subunit alpha-1	A	protein	354	Homo sapiens	P63096 (AlphaFold model)
Probable G-protein coupled receptor 174	R	protein	333	Homo sapiens	Q9BXC1 (AlphaFold model)
Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1	B	protein	338	Homo sapiens	P62873 (AlphaFold model)
Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2	C	protein	71	Homo sapiens	P59768 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>20YC_1 Guanine nucleotide-binding protein G(i) subunit alpha-1 (chains A)
MGCTLSAEDKAAVERSKMIDRNLREDGEKAAREVKLLLLGAGESGKNTIVKQMKIIHEAG
YSEEECKQYKAVVYSNTIQSIIAIIRAMGRLKIDFGDSARADDARQLFVLAGAAEEGFMT
AELAGVIKRLWKDSGVQACFNRSREYQLNDSAAYYLNDLDRIAQPNYIPTQQDVLRTRVK
TTGIVETHFTFKDLHFKMFDVGGQRSERKKWIHCFEGVTAIIFCVALSDYDLVLAEDEEM
NRMHESMKLFDSICNNKWFTDTSIILFLNKKDLFEEKIKKSPLTICYPEYAGSNTYEEAA
AYIQCQFEDLNKRKDTKEIYTHFTCSTDTKNVQFVFDAVTDVIIKNNLKDCGLF

Sequence of entity 2 (R), FASTA

>20YC_2 Probable G-protein coupled receptor 174 (chains R)
MPANYTCTRPDGDNTDFRYFIYAVTYTVILVPGLIGNILALWVFYGYMKETKRAVIFMIN
LAIADLLQVLSLPLRIFYYLNHDWPFGPGLCMFCFYLKYVNMYASIYFLVCISVRRFWFL
MYPFRFHDCKQKYDLYISIAGWLIICLACVLFPLLRTSDDTSGNRTKCFVDLPTRNVNLA
QSVVMMTIGELIGFVTPLLIVLYCTWKTVLSLQDKYPMAQDLGEKQKALKMILTCAGVFL
ICFAPYHFSFPLDFLVKSNEIKSCLARRVILIFHSVALCLASLNSCLDPVIYYFSTNEFR
RRLSRQDLHDSIQLHAKSFVSNHTASTMTPELC

Sequence of entity 3 (B), FASTA

>20YC_3 Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1 (chains B)
ELDQLRQEAEQLKNQIRDARKACADATLSQITNNIDPVGRIQMRTRRTLRGHLAKIYAMH
WGTDSRLLVSASQDGKLIIWDSYTTNKVHAIPLRSSWVMTCAYAPSGNYVACGGLDNICS
IYNLKTREGNVRVSRELAGHTGYLSCCRFLDDNQIVTSSGDTTCALWDIETGQQTTTFTG
HTGDVMSLSLAPDTRLFVSGACDASAKLWDVREGMCRQTFTGHESDINAICFFPNGNAFA
TGSDDATCRLFDLRADQELMTYSHDNIICGITSVSFSKSGRLLLAGYDDFNCNVWDALKA
DRAGVLAGHDNRVSCLGVTDDGMAVATGSWDSFLKIWN

Sequence of entity 4 (C), FASTA

>20YC_4 Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2 (chains C)
MASNNTASIAQARKLVEQLKMEANIDRIKVSKAAADLMAYCEAHAKEDPLLTPVPASENP
FREKKFFCAIL

Primary citation

Hydration network drives activation and G protein selectivity in GPR174. Dong, Y.-J., Xi, K., Zhang, Y.-Z. et al. To be published.

Other PDB entries of the same protein (UniProt P63096 (AlphaFold model), which also has an AlphaFold model), best resolution first:

6CRK 2.0 Å, Heterotrimeric G-protein in complex with an antibody fragment
3UMR 2.04 Å, Crystal structure of the G202D mutant of human G-alpha-i1
9P7Z 2.1 Å, NTSR1-Gi-NTS(8-13) Complex in the Canonical, AHD Open State (C-Open-Apo)
2OM2 2.2 Å, Crystal Structure Of Human G[alpha]i1 Bound To The Goloco Motif Of Rgs14
8YN9 2.3 Å, Cryo-EM structure of histamine H4 receptor in complex with histamine and Gi
9HYI 2.3 Å, DP81-bound serotonin 5-HT1A receptor - Gi Protein Complex
9O36 2.3 Å, CryoEM structure of mu-opioid receptor - Gi protein complex bound to fluornitrazene (FNZ)
9P80 2.3 Å, NTSR1-Gi-NTS(8-13) Complex in the Non-Canonical, AHD Open State (NC-Open-Apo)
8XXV 2.33 Å, Cryo-EM Structure of the Prostaglandin D2 Receptor 2-indomethacin Coupled to G Protein
3UMS 2.34 Å, Crystal structure of the G202A mutant of human G-alpha-i1
3ONW 2.38 Å, Structure of a G-alpha-i1 mutant with enhanced affinity for the RGS14 GoLoco motif.
20ZG 2.4 Å, Cryo-EM structure of the human neurotensin receptor 1 (hNTSR1)-Gi1 complex in the…

Browse structure collections

About this viewer

MolViewer shows 20YC 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.