6FGB: Human FcRn extra-cellular domain

Human FcRn extra-cellular domain complexed with Fab fragment of Rozanolixizumab. Determined by X-ray diffraction at 2.9 Å resolution. Released 29 Aug 2018.

Method: X-ray diffraction
Resolution: 2.9 Å
Organism: Homo sapiens
Chains: 4
Atoms: 6,141
Mol. weight: 97.35 kDa
Released: 29 Aug 2018

Explore 6FGB in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

6FGB contains 25 α-helices and 74 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: 9 helices, 18 β-strands

Element	Residues	Length	Sheet
β-strand	6-14	9	1
α-helix	17-18	2
β-strand	24-30	7	1
β-strand	33-39	7	1
β-strand	46-47	2	1
α-helix	49-53	5
α-helix	60-81	22
β-strand	89-98	10	1
β-strand	104-112	9	1
β-strand	115-121	7	1
β-strand	126-128	3	1
α-helix	132-142	11
α-helix	147-153	7
α-helix	154-158	5
α-helix	159-169	11
α-helix	171-175	5
β-strand	178	1	2
α-helix	179-180	2
β-strand	181-188	8	3
β-strand	193-203	11	3
β-strand	204	1	2
β-strand	208-214	7	4
β-strand	217-218	2	4
β-strand	223-228	6	3
β-strand	234-243	10	3
β-strand	250-256	7	4
β-strand	263-266	4	4

Chain B: 1 helix, 11 β-strands

Element	Residues	Length	Sheet
β-strand	3	1	5
α-helix	4-5	2
β-strand	6-11	6	6
β-strand	21-30	10	6
β-strand	31	1	5
β-strand	36-41	6	7
β-strand	44-45	2	7
β-strand	50-51	2	6
β-strand	55-56	2	6
β-strand	62-70	9	6
β-strand	78-83	6	7
β-strand	91-94	4	7

Chain H: 9 helices, 21 β-strands

Element	Residues	Length	Sheet
β-strand	6-7	2	15
β-strand	10-12	3	16
β-strand	18-23	6	15
α-helix	29-31	3
β-strand	34-39	6	16
β-strand	46-51	6	16
β-strand	58-60	3	16
β-strand	68-73	6	15
α-helix	74-76	3
β-strand	78-83	6	15
α-helix	88-90	3
β-strand	92-98	7	16
β-strand	111-115	5	16
α-helix	119-120	2
β-strand	121	1	17
α-helix	122-123	2
β-strand	124-128	5	18
α-helix	129-131	3
β-strand	139-149	11	18
β-strand	150	1	17
β-strand	155-158	4	19
α-helix	159-161	3
β-strand	167-169	3	18
α-helix	170-172	3
β-strand	173-175	3	18
β-strand	179-189	11	18
α-helix	192-195	4
β-strand	196	1	20
β-strand	199-204	6	19
β-strand	209-214	6	19

Chain L: 6 helices, 24 β-strands

Element	Residues	Length	Sheet
β-strand	4-7	4	8
β-strand	10-14	5	9
β-strand	19-25	7	8
β-strand	30	1	10
β-strand	36	1	10
β-strand	38-43	6	9
β-strand	50-54	5	9
β-strand	58-59	2	9
α-helix	60	1
β-strand	67-71	5	8
β-strand	75-80	6	8
α-helix	85-87	3
β-strand	89-95	7	9
β-strand	102-103	2	9
β-strand	107-112	6	9
β-strand	116	1	11
β-strand	119-123	5	12
α-helix	124-126	3
α-helix	127-131	5
β-strand	134-144	11	12
β-strand	145	1	11
β-strand	149-153	5	13
β-strand	154-155	2	14
β-strand	158-159	2	14
β-strand	164-168	5	12
α-helix	169-172	4
β-strand	178-187	10	12
α-helix	188-193	6
β-strand	196-203	8	13
β-strand	210-215	6	13

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
IgG receptor FcRn large subunit p51	A	protein	342	Homo sapiens	P55899 (AlphaFold model)
Beta-2-microglobulin	B	protein	99	Homo sapiens	P61769 (AlphaFold model)
1519.g57- Light chain	L	protein	219	Homo sapiens
1519.g57- Heavy chain	H	protein	228	Homo sapiens

Sequence of entity 1 (A), FASTA

>6FGB_1 IgG receptor FcRn large subunit p51 (chains A)
AESHLSLLYHLTAVSSPAPGTPAFWVSGWLGPQQYLSYNSLRGEAEPCGAWVWENQVSWY
WEKETTDLRIKEKLFLEAFKALGGKGPYTLQGLLGCELGPDNTSVPTAKFALNGEEFMNF
DLKQGTWGGDWPEALAISQRWQQQDKAANKELTFLLFSCPHRLREHLERGRGNLEWKEPP
SMRLKARPSSPGFSVLTCSAFSFYPPELQLRFLRNGLAAGTGQGDFGPNSDGSFHASSSL
TVKSGDEHHYCCIVQHAGLAQPLRVELESPAKSSVLVVGIVIGVLLLTAAAVGGALLWRR
MRSGLPAPWISLRGDDTGVLLPTPGEAQDADLKDVNVIPATA

Sequence of entity 2 (B), FASTA

>6FGB_2 Beta-2-microglobulin (chains B)
IQRTPKIQVYSRHPAENGKSNFLNCYVSGFHPSDIEVDLLKNGERIEKVEHSDLSFSKDW
SFYLLYYTEFTPTEKDEYACRVNHVTLSQPKIVKWDRDM

Sequence of entity 3 (L), FASTA

>6FGB_3 1519.g57- Light chain (chains L)
DIQMTQSPSSLSASVGDRVTITCKSSQSLVGASGKTYLYWLFQKPGKAPKRLIYLVSTLD
SGIPSRFSGSGSGTEFTLTISSLQPEDFATYYCLQGTHFPHTFGQGTKLEIKRTVAAPSV
FIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSL
SSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC

Sequence of entity 4 (H), FASTA

>6FGB_4 1519.g57- Heavy chain (chains H)
EVPLVESGGGLVQPGGSLRLSCAVSGFTFSNYGMVWVRQAPGKGLEWVAYIDSDGDNTYY
RDSVKGRFTISRDNAKSSLYLQMNSLRAEDTAVYYCTTGIVRPFLYWGQGTLVTVSSAST
KGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLY
SLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCAA

Primary citation

Generation and characterization of a high affinity anti-human FcRn antibody, rozanolixizumab, and the effects of different molecular formats on the reduction of plasma IgG concentration. Smith, B., Kiessling, A., Lledo-Garcia, R. et al. MAbs (2018) 10:1111-1130. DOI 10.1080/19420862.2018.1505464 · PubMed

Other PDB entries of the same protein (UniProt P55899 (AlphaFold model), which also has an AlphaFold model), best resolution first:

6C98 1.85 Å, Crystal structure of FcRn bound to UCB-84
6QIO 1.95 Å, Ternary complex of FcRn ectodomain, FcRn binding optimised human serum albumin and the…
6C97 2.0 Å, Crystal structure of FcRn at pH3
6C99 2.0 Å, Crystal structure of FcRn bound to UCB-303
9TF0 2.26 Å, Structure of echovirus 18 in complex with neonatal Fc receptor
6NHA 2.38 Å, Crystal structure of SYNT001, a human FcRn blocking monoclonal antibody
6LA6 2.39 Å, Cryo-EM structure of echovirus 11 complexed with its uncoating receptor FcRn at pH 7.4
4K71 2.4 Å, Crystal structure of a high affinity Human Serum Albumin variant bound to the Neonatal…
6WNA 2.4 Å, Next generation monomeric IgG4 Fc
9MI6 2.41 Å, Crystal structure of human FcRn in complex with nipocalimab Fab fragment
6QIP 2.45 Å, Ternary complex of FcRn ectodomain, FcRn binding optimised human serum albumin and the…
6WOL 2.49 Å, Next generation monomeric IgG4 Fc bound to neonatal Fc receptor

Browse structure collections

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