1IAO: Class II MHC I-ad

Class II MHC I-ad in complex with ovalbumin peptide 323-339. Determined by X-ray diffraction at 2.6 Å resolution. Released 4 Nov 1998.

Method: X-ray diffraction
Resolution: 2.6 Å
Organism: Mus musculus
Chains: 2
Atoms: 3,035
Mol. weight: 47.64 kDa
Ligands: NAG
Released: 4 Nov 1998

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

Secondary structure: helices and β-sheets

1IAO contains 12 α-helices and 31 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 A: 3 helices, 14 β-strands

Element	Residues	Length	Sheet
β-strand	4-14	11	1
β-strand	19-26	8	1
β-strand	29-35	7	1
β-strand	40-43	4	1
α-helix	46-49	4
β-strand	53	1	2
α-helix	56-76	21
α-helix	82-84	3
β-strand	88	1	3
β-strand	91-93	3	4
β-strand	103-112	10	4
β-strand	118-121	4	5
β-strand	133-134	2	4
β-strand	138-139	2	4
β-strand	145-153	9	4
β-strand	162-166	5	5
β-strand	174-177	4	5

Chain B: 9 helices, 17 β-strands

Element	Residues	Length	Sheet
β-strand	323P	1	2
α-helix	324P-326P	3
α-helix	328P-330P	3
β-strand	8-18	11	1
β-strand	23-32	10	1
β-strand	35-41	7	1
β-strand	47-49	3	1
α-helix	52-54	3
α-helix	55-63	9
α-helix	65-72	8
α-helix	74	1
α-helix	75-80	6
α-helix	81-84	4
α-helix	87-89	3
β-strand	95	1	6
β-strand	98	1	7
β-strand	101-103	3	7
β-strand	113-122	10	7
β-strand	123	1	6
β-strand	128-133	6	8
β-strand	136-138	3	8
β-strand	142-144	3	7
β-strand	148-149	2	7
β-strand	155-163	9	7
β-strand	170-176	7	8
β-strand	184-1T	6	8

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
MHC class II I-ad	A	protein	194	Mus musculus	P04228 (AlphaFold model)
MHC class II I-ad	B	protein	222	Mus musculus	P01921 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>1IAO_1 MHC CLASS II I-AD (chains A)
EDDIEADHVGFYGTTVYQSPGDIGQYTHEFDGDELFYVDLDKKKTVWRLPEFGQLILFEP
QGGLQNIAAEKHNLGILTKRSNFTPATNEAPQATVFPKSPVLLGQPNTLICFVDNIFPPV
INITWLRNSKSVTDGVYETSFLVNRDHSFHKLSYLTFIPSDDDIYDCKVEHWGLEEPVLK
HWEPEISSADLVPR

Sequence of entity 2 (B), FASTA

>1IAO_2 MHC CLASS II I-AD (chains B)
RGISQAVHAAHAEINEAGRGSGSGSGNSERHFVVQFKGECYYTNGTQRIRLVTRYIYNRE
EYVRYDSDVGEYRAVTELGRPDAEYWNSQPEILDRTRAEVDTACRHNYEGPETSTSLRRL
EQPNVAISLSRTEALNHHNTLVCSVTDFYPAKIKVRWFRNGQEETVGVSSTQLIRNGDWT
FQVLVMLEMTPHQGEVYTCHVEHPSLKSPITVEWSSADLVPR

Ligands and cofactors

ID	Name	Formula	Copies
NAG	2-acetamido-2-deoxy-beta-D-glucopyranose	C8 H15 N O6	1

Primary citation

Crystal structures of two I-Ad-peptide complexes reveal that high affinity can be achieved without large anchor residues. Scott, C.A., Peterson, P.A., Teyton, L. et al. Immunity (1998) 8:319-329. DOI 10.1016/S1074-7613(00)80537-3 · PubMed

Other PDB entries of the same protein (UniProt P04228 (AlphaFold model), which also has an AlphaFold model), best resolution first:

6BLQ 1.8 Å, Crystal Structure of IAg7 in complex with insulin mimotope p8E9E
7QHP 1.82 Å, Structure of I-Ag7 with a bound hybrid insulin peptide
6BLR 1.96 Å, Crystal Structure of IAg7 in complex with insulin mimotope p8E9E6SS
6BLX 2.32 Å, Crystal structure of IAg7 in complex with insulin mimotope p8G9E
2IAD 2.4 Å, Class II MHC I-ad in complex with an influenza hemagglutinin peptide 126-138
5DMK 2.45 Å, Crystal Structure of IAg7 in complex with RLGL-WE14
1ES0 2.6 Å, Crystal structure of the murine class II allele I-A(G7) complexed with the glutamic acid…
7Z50 2.65 Å, Structure of the highly diabetogenic 4.1-T cell receptor targeting a hybrid insulin…
3MBE 2.89 Å, TCR 21.30 in complex with MHC class II I-Ag7HEL(11-27)
7RDV 2.9 Å, TFH TCR bound to MHC Class II IAd presenting aggrecan epitope
3CUP 3.09 Å, Crystal structure of the MHC class II molecule I-Ag7 in complex with the peptide…
1F3J 3.1 Å, Histocompatibility antigen I-AG7

Browse structure collections

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