1I1A: Neonatal fc receptor

Crystal structure of the neonatal fc receptor complexed with a heterodimeric fc. Determined by X-ray diffraction at 2.8 Å resolution. Released 14 Feb 2001.

Method: X-ray diffraction
Resolution: 2.8 Å
Organism: Rattus norvegicus
Chains: 4
Atoms: 6,526
Mol. weight: 98.95 kDa
Ligands: NAG, CYS
Released: 14 Feb 2001

Explore 1I1A in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

1I1A contains 25 α-helices and 66 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: 7 helices, 16 β-strands

Element	Residues	Length	Sheet
β-strand	7-14	8	1
β-strand	24-30	7	1
β-strand	33-39	7	1
β-strand	46-47	2	1
α-helix	49-51	3
α-helix	60-85	26
β-strand	91-100	10	1
β-strand	106-114	9	1
β-strand	117-123	7	1
β-strand	128-130	3	1
α-helix	134-144	11
α-helix	147-155	9
α-helix	156-160	5
α-helix	161-176	16
β-strand	183-189	7	2
β-strand	195-205	11	2
β-strand	211-216	6	3
β-strand	219-220	2	3
β-strand	226-230	5	2
β-strand	236-245	10	2
α-helix	249-251	3
β-strand	252-257	6	3
β-strand	265-267	3	3

Chain B: 2 helices, 11 β-strands

Element	Residues	Length	Sheet
β-strand	3	1	4
β-strand	6-11	6	5
β-strand	21-30	10	5
β-strand	31	1	4
β-strand	36-41	6	6
β-strand	44-45	2	6
β-strand	50-51	2	5
α-helix	52-54	3
β-strand	55-56	2	5
β-strand	62-70	9	5
β-strand	78-83	6	6
β-strand	91-94	4	6
α-helix	95	1

Chain C: 9 helices, 19 β-strands

Element	Residues	Length	Sheet
β-strand	240-243	4	7
α-helix	244-246	3
α-helix	247-251	5
β-strand	258-263	6	7
β-strand	274-279	6	8
β-strand	283-284	2	8
β-strand	288-294	7	7
β-strand	300-307	8	7
α-helix	310-314	5
β-strand	319-324	6	8
β-strand	332-336	5	8
α-helix	338-340	3
β-strand	344	1	9
β-strand	347-351	5	10
α-helix	352-354	3
α-helix	355-357	3
β-strand	362-372	11	10
β-strand	373	1	9
β-strand	378-383	6	11
β-strand	386-387	2	11
β-strand	391-393	3	10
α-helix	394-396	3
β-strand	397-398	2	10
β-strand	404-413	10	10
α-helix	414-418	5
β-strand	423-428	6	11
α-helix	433-435	3
β-strand	436-441	6	11

Chain D: 7 helices, 20 β-strands

Element	Residues	Length	Sheet
α-helix	247-250	4
α-helix	256-257	2
β-strand	258-259	2	12
β-strand	276-278	3	13
β-strand	283	1	13
β-strand	288-290	3	14
β-strand	295	1	15
β-strand	299	1	15
β-strand	303-305	3	14
β-strand	306-307	2	12
α-helix	310-313	4
β-strand	320-322	3	13
β-strand	344	1	16
β-strand	347-351	5	17
α-helix	352-354	3
β-strand	362-372	11	17
β-strand	373	1	16
β-strand	379-383	5	18
β-strand	386-387	2	18
β-strand	391-393	3	17
α-helix	394-396	3
β-strand	397-398	2	17
β-strand	404-413	10	17
α-helix	414-418	5
β-strand	423-428	6	18
α-helix	433-435	3
β-strand	436-441	6	18

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Neonatal fc receptor A	A	protein	269	Rattus norvegicus	P13599 (AlphaFold model)
Beta-2-microglobulin	B	protein	99	Rattus norvegicus	P07151 (AlphaFold model)
Ig gamma-2A chain C region	C	protein	225	Rattus norvegicus	P20760 (AlphaFold model)
Ig gamma-2A chain C region	D	protein	239	Rattus norvegicus	P20760 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>1I1A_1 NEONATAL FC RECEPTOR A (chains A)
AEPRLPLMYHLAAVSDLSTGLPSFWATGWLGAQQYLTYNNLRQEADPCGAWIWENQVSWY
WEKETTDLKSKEQLFLEAIRTLENQINGTFTLQGLLGCELAPDNSSLPTAVFALNGEEFM
RFNPRTGNWSGEWPETDIVGNLWMKQPEAARKESEFLLTSCPERLLGHLERGRQNLEWKE
PPSMRLKARPGNSGSSVLTCAAFSFYPPELKFRFLRNGLASGSGNCSTGPNGDGSFHAWS
LLEVKRGDEHHYQCQVEHEGLAQPLTVDL

Sequence of entity 2 (B), FASTA

>1I1A_2 BETA-2-MICROGLOBULIN (chains B)
IQKTPQIQVYSRHPPENGKPNFLNCYVSQFHPPQIEIELLKNGKKIPNIEMSDLSFSKDW
SFYILAHTEFTPTETDVYACRVKHVTLKEPKTVTWDRDM

Sequence of entity 3 (C), FASTA

>1I1A_3 IG GAMMA-2A CHAIN C REGION (chains C)
VPRECNPCGCTGSEVSSVFIFPPKTKDVLTITLTPKVTCVVVDISQNDPEVRFSWFIDDV
EVHTAQTHAPEKQSNSTLRSVSELPIVHRDWLNGKTFKCKVNSGAFPAPIEKSISKPEGT
PRGPQVYTMAPPKEEMTQSQVSITCMVKGFYPPDIYTEWKMNGQPQENYKNTPPTMDTDG
SYFLYSKLNVKKETWQQGNTFTCSVLHEGLHNHHTEKSLSHSPGK

Sequence of entity 4 (D), FASTA

>1I1A_4 IG GAMMA-2A CHAIN C REGION (chains D)
VPRECNPCGCTGSEVSSVFIFPPKTKDVLGGGLTPKVTCVVVDISQNDPEVRFSWFIDDV
EVHTAQTHAPEKQSNSTLRSVSELPIVERDWLNGKTFKCKVNSGAFPAPIEKSISKPEGT
PRGPQVYTMAPPKEEMTQSQVSITCMVKGFYPPDIYTEWKMNGQPQENYKNTPPTMDTDG
SYFLYSKLNVKKETWQQGNTFTCSVLHEGLENEHTEKSLSHSPGKGIEGRGSSHHHHHH

Ligands and cofactors

ID	Name	Formula	Copies
NAG	2-acetamido-2-deoxy-beta-D-glucopyranose	C8 H15 N O6	2
CYS	Cysteine	C3 H7 N O2 S	2

Primary citation

Crystal structure at 2.8 A of an FcRn/heterodimeric Fc complex: mechanism of pH-dependent binding. Martin, W.L., West Jr., A.P., Gan, L. et al. Mol Cell (2001) 7:867-877. DOI 10.1016/S1097-2765(01)00230-1 · PubMed

Other PDB entries of the same protein (UniProt P13599 (AlphaFold model), which also has an AlphaFold model), best resolution first:

3FRU 2.2 Å, Neonatal fc receptor, PH 6.5
1FRT 4.5 Å, Crystal structure of the complex of rat neonatal fc receptor with fc

Browse structure collections

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