9L16: C-C motif chemokine 21

A local Cryo_EM structure of CCR7 complex with CCL21. Determined by electron microscopy at 3.5 Å resolution. Released 17 Dec 2025.

Method: Electron microscopy
Resolution: 3.5 Å
Organism: Homo sapiens
Chains: 2
Atoms: 2,968
Mol. weight: 48.05 kDa
Released: 17 Dec 2025

Explore 9L16 in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9L16 contains 18 α-helices and 6 β-strands across 2 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 L: 4 helices, 3 β-strands

Element	Residues	Length	Sheet
α-helix	16-18	3
α-helix	19-21	3
β-strand	22-25	4	1
β-strand	39-43	5	1
α-helix	49-50	2
β-strand	51-53	3	1
α-helix	58-66	9

Chain R: 14 helices, 3 β-strands

Element	Residues	Length	Sheet
α-helix	41-43	3
β-strand	46	1	1
α-helix	51-86	36
α-helix	92-119	28
α-helix	126-158	33
α-helix	161-164	4
α-helix	168-189	22
α-helix	191-196	6
β-strand	198-202	5	2
β-strand	206-211	6	2
α-helix	217-225	9
α-helix	226-233	8
α-helix	234-250	17
α-helix	259-291	33
α-helix	298-322	25
α-helix	323-327	5
α-helix	331-342	12

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
C-C motif chemokine 21	L	protein	78	Homo sapiens	O00585 (AlphaFold model)
C-C chemokine receptor type 7	R	protein	344	Homo sapiens	P32248 (AlphaFold model)

Sequence of entity 1 (L), FASTA

>9L16_1 C-C motif chemokine 21 (chains L)
SDGGAQDCCLKYSQRKIPAKVVRSYRKQEPSLGCSIPAILFLPRKRSQAELCADPKELWV
QQLMQHLDKTPSPQKPAQ

Sequence of entity 2 (R), FASTA

>9L16_2 C-C chemokine receptor type 7 (chains R)
QDEVTDDYIGDNTTVDYTLFESLCSKKDVRNFKAWFLPIMYSIICFVGLLGNGLVVLTYI
YFKRLKTMTDTYLLNLAVADILFLLTLPFWAYSAAKSWVFGVHFCKLIFAIYKMSFFSGM
LLLLCISIDRYVAIVQAVSAHRHRARVLLISKLSCVGIWILATVLSIPELLYSDLQRSSS
EQAMRCSLITEHVEAFITIQVAQMVIGFLVPLLAMSFCYLVIIRTLLQARNFERNKAIKV
IIAVVVVFIVFQLPYNGVVLAQTVANFNITSSTCELSKQLNIAYDVTYSLACVRCCVNPF
LYAFIGVKFRNDLFKLFKDLGCLSQEQLRQWSSCRHIRRSSMSV

Primary citation

A local Cryo_EM structure of CCR7 complex with CCL21. Duan, J., Yuan, Q., Cao, Y. To be published.

Other PDB entries of the same protein (UniProt O00585 (AlphaFold model), which also has an AlphaFold model), best resolution first:

5EKI 1.9 Å, Crystal Structure of Truncated CCL21
9XHI 3.2 Å, Structure of the CCL21-CCR7-Gi-scFv16 complex
9KO4 3.3 Å, A Cryo_EM structure of CCR7 complex with CCL21
2L4N Solution Structure of the Chemokine CCL21

Browse structure collections

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