7KQ7: IL21R

Crystal structure of IL21R in complex with an antibody Fab fragment. Determined by X-ray diffraction at 2.2 Å resolution. Released 7 Apr 2021.

Method: X-ray diffraction
Resolution: 2.2 Å
Organisms: Rattus norvegicus, Homo sapiens
Chains: 3
Atoms: 5,111
Mol. weight: 72.26 kDa
Released: 7 Apr 2021

Explore 7KQ7 in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

7KQ7 contains 23 α-helices and 63 β-strands across 3 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 B: 6 helices, 18 β-strands

Element	Residues	Length	Sheet
β-strand	5-8	4	13
β-strand	13-19	7	13
β-strand	27-32	6	14
α-helix	42-44	3
β-strand	45-48	4	14
β-strand	49-53	5	13
β-strand	57-63	7	13
β-strand	74-80	7	14
β-strand	87-94	8	14
α-helix	95-97	3
β-strand	99	1	13
α-helix	101-104	4
β-strand	105-108	4	15
β-strand	111	1	15
β-strand	115-120	6	15
α-helix	126-131	6
β-strand	135-144	10	16
α-helix	151-152	2
β-strand	153-157	5	16
β-strand	163-166	4	15
β-strand	176-185	10	16
β-strand	193	1	13
α-helix	195-201	7
β-strand	202-205	4	16

Chain H: 10 helices, 22 β-strands

Element	Residues	Length	Sheet
β-strand	3-7	5	1
β-strand	11-12	2	2
β-strand	18-25	8	1
α-helix	29-31	3
β-strand	33-39	7	3
β-strand	45-52	8	3
β-strand	57-60	4	3
α-helix	62-64	3
β-strand	68-73	6	1
α-helix	74-76	3
β-strand	78-83	6	1
α-helix	88-90	3
β-strand	92-99	8	3
β-strand	111	1	3
β-strand	115-117	3	3
β-strand	118-119	2	2
α-helix	123-124	2
β-strand	125	1	4
α-helix	126-127	2
β-strand	128-132	5	5
β-strand	144-153	10	5
β-strand	154	1	4
β-strand	159-162	4	6
α-helix	163-165	3
β-strand	172-173	2	5
α-helix	174-176	3
β-strand	177-178	2	5
β-strand	184-192	9	5
α-helix	195-199	5
β-strand	202-208	7	6
α-helix	209-211	3
β-strand	213-219	7	6

Chain L: 7 helices, 23 β-strands

Element	Residues	Length	Sheet
β-strand	4-7	4	7
β-strand	10-14	5	8
β-strand	19-25	7	7
β-strand	30-31	2	9
β-strand	34-35	2	9
β-strand	37-42	6	8
β-strand	49-53	5	8
β-strand	57-58	2	8
α-helix	59	1
β-strand	66-71	6	7
β-strand	74-79	6	7
α-helix	84-86	3
β-strand	88-94	7	8
α-helix	100	1
β-strand	101-102	2	8
β-strand	106-111	6	8
β-strand	115	1	10
β-strand	118-122	5	11
α-helix	123-125	3
α-helix	126-129	4
β-strand	133-143	11	11
β-strand	144	1	10
β-strand	149-154	6	12
β-strand	157	1	12
β-strand	163-167	5	11
α-helix	168-171	4
β-strand	177-186	10	11
α-helix	187-191	5
β-strand	196-201	6	12
β-strand	209-213	5	12

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Antibody heavy chain	H	protein	222	Rattus norvegicus
Antibody light chain	L	protein	218	Rattus norvegicus
Interleukin-21 receptor	B	protein	214	Homo sapiens	Q9HBE5 (AlphaFold model)

Sequence of entity 1 (H), FASTA

>7KQ7_1 Antibody heavy chain (chains H)
EVQLVESGGGLVQPGRSLRLSCAASGVTFSDYHMAWVRQAPKKGLEWVATIIYDAARTYY
RDSVKGRFTISRDNAKNSLYLQMNSLRAEDTAVYYCATWQTTGTPGWFAYWGQGTLVTVS
SASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQS
SGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPK

Sequence of entity 2 (L), FASTA

>7KQ7_2 Antibody light chain (chains L)
DIQMTQSPSSLSASVGDRVTITCGASQSVSISRFNLMHWYQQKPGHQPKLLIYRASNLAS
GVPSRFSGSGSGTDFTLTINPLQAEDFATYYCQQSRESPPTFGGGTKVEIKRTVAAPSVF
IFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLS
STLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC

Sequence of entity 3 (B), FASTA

>7KQ7_3 Interleukin-21 receptor (chains B)
CPDLVCYTDYLQTVICILEMWNLHPSTLTLTWQDQYEELKDEATSCSLHRSAHNATHATY
TCHMDVFHFMADDIFSVNITDQSGNYSQECGSFLLAESIKPAPPFNVTVTFSGQYNISWR
SDYEDPAFYMLKGKLQYELQYRNRGDPWAVSPRRKLISVDSRSVSLLPLEFRKDSSYELQ
VRAGPMPGSSYQGTWSEWSDPVIFQTQSEELKEG

Primary citation

Combining random mutagenesis, structure-guided design and next-generation sequencing to mitigate polyreactivity of an anti-IL-21R antibody. Campbell, S.M., DeBartolo, J., Apgar, J.R. et al. MAbs (2021) 13:1883239-1883239. DOI 10.1080/19420862.2021.1883239 · PubMed

Other PDB entries of the same protein (UniProt Q9HBE5 (AlphaFold model), which also has an AlphaFold model), best resolution first:

6PLH 1.6 Å, FAB fragment complexed with C-mannosylated tryptophan peptide
9E2T 2.28 Å, Structure of a de novo designed interleukin-21 mimetic complex with IL-21R and IL-2Rg
4NZD 2.75 Å, Interleukin 21 receptor
3TGX 2.8 Å, IL-21:IL21R complex
8ENT 2.83 Å, Interleukin-21 signaling complex with IL-21R and IL-2Rg

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