1I8L: Human B7-1/CTLA-4 co-stimulatory complex

Human B7-1/CTLA-4 co-stimulatory complex. Determined by X-ray diffraction at 3.0 Å resolution. Released 4 Apr 2001.

Method: X-ray diffraction
Resolution: 3.0 Å
Organism: Homo sapiens
Chains: 4
Atoms: 5,108
Mol. weight: 79.09 kDa
Ligands: NAG, MAN
Released: 4 Apr 2001

Explore 1I8L in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

1I8L contains 9 α-helices and 59 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: 3 helices, 18 β-strands

Element	Residues	Length	Sheet
β-strand	2-7	6	1
β-strand	12-14	3	2
α-helix	22-25	4
β-strand	28-34	7	1
β-strand	37-43	7	1
β-strand	46-49	4	1
β-strand	57-60	4	2
β-strand	66-69	4	2
α-helix	74-76	3
β-strand	78-88	11	1
β-strand	91-105	15	1
α-helix	107-111	5
β-strand	112-117	6	3
β-strand	123-133	11	3
β-strand	137-142	6	4
β-strand	147	1	4
β-strand	153-157	5	3
β-strand	164-173	10	3
β-strand	179-186	8	4
β-strand	189-191	3	4
β-strand	194-196	3	4

Chain B: 3 helices, 18 β-strands

Element	Residues	Length	Sheet
β-strand	2-7	6	5
β-strand	12-14	3	6
α-helix	22-25	4
β-strand	28-34	7	5
β-strand	37-43	7	5
β-strand	46	1	5
β-strand	49	1	5
β-strand	57-60	4	6
β-strand	66-69	4	6
α-helix	74-76	3
β-strand	78-88	11	5
β-strand	91-105	15	5
α-helix	107-111	5
β-strand	112-117	6	7
β-strand	123-133	11	7
β-strand	139-142	4	8
β-strand	147	1	8
β-strand	152-157	6	7
β-strand	164-173	10	7
β-strand	178-186	9	8
β-strand	189-197	9	8

Chain C: 2 helices, 12 β-strands

Element	Residues	Length	Sheet
β-strand	5-6	2	9
β-strand	10-12	3	10
β-strand	19-25	7	9
β-strand	33-41	9	10
β-strand	48-55	8	10
β-strand	56	1	11
β-strand	58	1	11
β-strand	72	1	9
β-strand	76-81	6	9
α-helix	86-88	3
β-strand	90-100	11	10
α-helix	104	1
β-strand	105-108	4	10
β-strand	112-115	4	10

Chain D: 1 helix, 11 β-strands

Element	Residues	Length	Sheet
β-strand	5-6	2	12
β-strand	10-12	3	13
β-strand	21-25	5	12
β-strand	33-42	10	13
β-strand	45-54	10	13
β-strand	72-73	2	12
β-strand	76-79	4	12
β-strand	90-92	3	13
β-strand	94-100	7	13
α-helix	104	1
β-strand	105-108	4	13
β-strand	112-115	4	13

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
T lymphocyte activation antigen CD80	A, B	protein	208	Homo sapiens	P33681 (AlphaFold model)
Cytotoxic T-lymphocyte protein 4	C, D	protein	126	Homo sapiens	P16410 (AlphaFold model)

Sequence of entity 1 (A, B), FASTA

>1I8L_1 T LYMPHOCYTE ACTIVATION ANTIGEN CD80 (chains A, B)
VIHVTKEVKEVATLSCGHNVSVEELAQTRIYWQKEKKMVLTMMSGDMNIWPEYKNRTIFD
ITNNLSIVILALRPSDEGTYECVVLKYEKDAFKREHLAEVTLSVKADFPTPSISDFEIPT
SNIRRIICSTSGGFPEPHLSWLENGEELNAINTTVSQDPETELYAVSSKLDFNMTTNHSF
MCLIKYGHLRVNQTFNWNTTKQEHFPDN

Sequence of entity 2 (C, D), FASTA

>1I8L_2 CYTOTOXIC T-LYMPHOCYTE PROTEIN 4 (chains C, D)
KAMHVAQPAVVLASSRGIASFVCEYASPGKATEVRVTVLRQADSQVTEVCAATYMMGNEL
TFLDDSICTGTSSGNQVNLTIQGLRAMDTGLYICKVELMYPPPYYLGIGNGAQIYVIDPE
PCPDSD

Ligands and cofactors

ID	Name	Formula	Copies
NAG	2-acetamido-2-deoxy-beta-D-glucopyranose	C8 H15 N O6	18
MAN	alpha-D-mannopyranose	C6 H12 O6	2

Primary citation

Crystal structure of the B7-1/CTLA-4 complex that inhibits human immune responses. Stamper, C.C., Zhang, Y., Tobin, J.F. et al. Nature (2001) 410:608-611. DOI 10.1038/35069118 · PubMed

Other PDB entries of the same protein (UniProt P33681 (AlphaFold model), which also has an AlphaFold model), best resolution first:

8FXW 2.7 Å, Cryo-EM structure of cowpox virus M2 in complex with human B7.1 (hexameric ring)
8FXZ 2.86 Å, Cryo-EM structure of cowpox virus M2 in complex with human B7.1 (heptameric ring)
1DR9 3.0 Å, Crystal structure of a soluble form of B7-1 (CD80)
8HXA 3.04 Å, Cryo-EM structure of MPXV M2 in complex with human B7.1
7TPS 3.15 Å, Crystal structure of ALPN-202 (engineered CD80 vIgD) in complex with PD-L1

Browse structure collections

About this viewer

MolViewer shows 1I8L directly in your browser with nothing to install. Switch between cartoon, ball-and-stick, spacefill and surface views, color by chain, secondary structure or B-factor, measure distances, angles and dihedrals, and share or embed the view.