9KV8: Human TLQP21

Structure of human TLQP21 bound to mouse C3aR in complex with Go. Determined by electron microscopy at 3.17 Å resolution. Released 26 Nov 2025.

Method: Electron microscopy
Resolution: 3.17 Å
Organisms: Homo sapiens, Mus musculus
Chains: 6
Atoms: 8,201
Mol. weight: 163.08 kDa
Released: 26 Nov 2025

Explore 9KV8 in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9KV8 contains 34 α-helices and 62 β-strands across 6 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: 9 helices, 6 β-strands

Element	Residues	Length	Sheet
α-helix	9-31	23
β-strand	34-40	7	2
α-helix	46-52	7
β-strand	186-191	6	2
β-strand	196-201	6	2
α-helix	209-211	3
α-helix	213-218	6
β-strand	221-227	7	2
α-helix	246-255	10
β-strand	264-270	7	2
α-helix	272-281	10
α-helix	284-286	3
α-helix	297-309	13
β-strand	320-323	4	2
α-helix	331-351	21

Chain B: 4 helices, 30 β-strands

Element	Residues	Length	Sheet
α-helix	4-24	21
α-helix	30-34	5
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
β-strand	100-105	6	5
β-strand	111-116	6	5
β-strand	121-125	5	5
β-strand	134-139	6	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	221-223	3	7
β-strand	229	1	8
β-strand	233-234	2	9
β-strand	240-242	3	9
β-strand	245	1	8
β-strand	250-254	5	9
β-strand	259-264	6	9
α-helix	272	1
β-strand	273-278	6	10
β-strand	284-289	6	10
β-strand	294-298	5	10
β-strand	304-307	4	10
β-strand	315-320	6	3
β-strand	327-331	5	3
β-strand	336-339	4	3

Chain C: 13 helices, 2 β-strands

Element	Residues	Length	Sheet
α-helix	21-46	26
α-helix	47-51	5
α-helix	58-83	26
α-helix	93-125	33
α-helix	127-133	7
α-helix	136-160	25
β-strand	161-162	2	1
β-strand	173-174	2	1
α-helix	324-334	11
α-helix	335-339	5
α-helix	340-357	18
α-helix	365-395	31
α-helix	401-428	28
α-helix	429-431	3
α-helix	433-442	10

Chain D: 1 helix, 0 β-strands

Element	Residues	Length	Sheet
α-helix	10-15	6

Chain G: 3 helices, 0 β-strands

Element	Residues	Length
α-helix	8-23	16
α-helix	30-43	14
α-helix	45-47	3

Chain H: 4 helices, 24 β-strands

Element	Residues	Length	Sheet
β-strand	3-7	5	11
β-strand	10-12	3	12
β-strand	18-25	8	11
α-helix	29-31	3
β-strand	33-39	7	13
β-strand	45-51	7	13
α-helix	53-55	3
β-strand	58-60	3	13
β-strand	68-71	4	11
β-strand	78-83	6	11
α-helix	88-90	3
β-strand	93-99	7	13
β-strand	111	1	13
β-strand	115-116	2	13
β-strand	117-119	3	12
β-strand	146	1	14
β-strand	155-159	5	15
β-strand	166	1	16
β-strand	172	1	16
β-strand	174-179	6	14
β-strand	186-190	5	14
β-strand	194-195	2	14
α-helix	196	1
β-strand	203-208	6	15
β-strand	211-216	6	15
β-strand	225-231	7	14
β-strand	239	1	14
β-strand	243-245	3	14

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Muscarinic acetylcholine receptor M4,C3a anaphylatoxin chemotactic receptor	C	protein	533	Homo sapiens, Mus musculus	O09047 (AlphaFold model), P08173 (AlphaFold model)
VGF-derived peptide TLQP-21	D	protein	21	Homo sapiens	O15240 (AlphaFold model)
Guanine nucleotide-binding protein G(o) subunit alpha	A	protein	250	Homo sapiens	P09471 (AlphaFold model)
Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1	B	protein	350	Homo sapiens	P62873
Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2	G	protein	71	Homo sapiens	P59768
Antibody fragment - ScFv16	H	protein	248	Mus musculus

Sequence of entity 1 (C), FASTA

>9KV8_1 Muscarinic acetylcholine receptor M4,C3a anaphylatoxin chemotactic receptor (chains C)
MGKTIIALSYIFCLVFADYKDDDDAANFTPVNGSSGNQSVRLVTSSSLEVLFQGPGSESF
DADTNSTDLHSRPLFQPQDIASMVILGLTCLLGLLGNGLVLWVAGVKMKTTVNTVWFLHL
TLADFLCCLSLPFSLAHLILQGHWPYGLFLCKLIPSIIILNMFASVFLLTAISLDRCLIV
HKPIWCQNHRNVRTAFAICGCVWVVAFVMCVPVFVYRDLFIMDNRSICRYNFDSSRSYDY
WDYVYKLSLPESNSTDNSTAQLTGHMNDRSAPSSVQARDYFWTVTTALQSQPFLTSPEDS
FSLDSANQQPHYGGKPPNVLTAAVPSGFPVEDRKSNTLNADAFLSAHTELFPTASSGHLY
PYDFQGDYVDQFTYDNHVPTPLMAITITRLVVGFLVPFFIMVICYSLIVFRMRKTNFTKS
RNKTFRVAVAVVTVFFICWTPYHLVGVLLLITDPESSLGEAVMSWDHMSIALASANSCFN
PFLYALLGKDFRKKARQSIKGILEAAFSEELTHSTNCTQDKASSKRNNMSTDV

Sequence of entity 2 (D), FASTA

>9KV8_2 VGF-derived peptide TLQP-21 (chains D)
TLQPPSALRRRHYHHALPPSR

Sequence of entity 3 (A), FASTA

>9KV8_3 Guanine nucleotide-binding protein G(o) subunit alpha (chains A)
MGHHHHHHENLYFQGTLSAEERAALERSKAIEKNLKEDGISAAKDVKLLLLGADNSGKST
IVKQMKIIHGGSGGSGGTTGIVETHFTFKNLHFRLFDVGGQRSERKKWIHCFEDVTAIIF
CVDLSDYDQVLHEDETTNRMHESLMLFDSICNNKFFIDTSIILFLNKKDLFGEKIKKSPL
TICFPEYTGPNTYEDAAAYIQAQFESKNRSPNKEIYCHMTCATDTNNAQVIFDAVTDIII
ANNLRGCGLY

Sequence of entity 4 (B), FASTA

>9KV8_4 Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1 (chains B)
MHHHHHHGSSGSELDQLRQEAEQLKNQIRDARKACADATLSQITNNIDPVGRIQMRTRRT
LRGHLAKIYAMHWGTDSRLLVSASQDGKLIIWDSYTTNKVHAIPLRSSWVMTCAYAPSGN
YVACGGLDNICSIYNLKTREGNVRVSRELAGHTGYLSCCRFLDDNQIVTSSGDTTCALWD
IETGQQTTTFTGHTGDVMSLSLAPDTRLFVSGACDASAKLWDVREGMCRQTFTGHESDIN
AICFFPNGNAFATGSDDATCRLFDLRADQELMTYSHDNIICGITSVSFSKSGRLLLAGYD
DFNCNVWDALKADRAGVLAGHDNRVSCLGVTDDGMAVATGSWDSFLKIWN

Sequence of entity 5 (G), FASTA

>9KV8_5 Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2 (chains G)
MASNNTASIAQARKLVEQLKMEANIDRIKVSKAAADLMAYCEAHAKEDPLLTPVPASENP
FREKKFFCAIL

Sequence of entity 6 (H), FASTA

>9KV8_6 Antibody fragment - ScFv16 (chains H)
DVQLVESGGGLVQPGGSRKLSCSASGFAFSSFGMHWVRQAPEKGLEWVAYISSGSGTIYY
ADTVKGRFTISRDDPKNTLFLQMTSLRSEDTAMYYCVRSIYYYGSSPFDFWGQGTTLTVS
SGGGGSGGGGSGGGGSDIVMTQATSSVPVTPGESVSISCRSSKSLLHSNGNTYLYWFLQR
PGQSPQLLIYRMSNLASGVPDRFSGSGSGTAFTLTISRLEAEDVGVYYCMQHLEYPLTFG
AGTKLELK

Primary citation

Molecular fingerprints of a convergent mechanism orchestrating diverse ligand recognition and species-specific pharmacology at the complement anaphylatoxin receptors. Mishra, S., Yadav, M.K., Dalal, A. et al. bioRxiv (2025). DOI 10.1101/2025.05.26.656101 · PubMed

Other PDB entries of the same protein (UniProt O09047 (AlphaFold model), which also has an AlphaFold model), best resolution first:

9KV6 2.88 Å, Structure of mouse TLQP21 bound to mouse C3aR in complex with Go
9KZ8 3.3 Å, Structure of EP67 bound mouse C3aR in complex with Go
9UMJ 3.38 Å, Structure of EP54 bound mouse C3aR in complex with Go
9KZK 3.54 Å, Structure of mouse C3a bound mouse C3aR in complex with Go
9L0H 3.57 Å, Structure of JR14a bound mouse C3aR in complex with Go

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