PDBe 3iu3

X-ray diffraction
2.9Å resolution

Crystal structure of the Fab fragment of therapeutic antibody Basiliximab in complex with IL-2Ra (CD25) ectodomain


Function and Biology Details

Structure analysis Details

Assembly composition:
hetero trimer (preferred)
Entry contents:
3 distinct polypeptide molecules
Macromolecules (3 distinct):
Interleukin-2 receptor subunit alpha Chains: I, J, K
Molecule details ›
Chains: I, J, K
Length: 223 amino acids
Theoretical weight: 25.39 KDa
Source organism: Homo sapiens
Expression system: Spodoptera frugiperda
  • Canonical: P01589 (Residues: 22-238; Coverage: 87%)
Gene name: IL2RA
Sequence domains: Sushi repeat (SCR repeat)
Structure domains: Complement Module, domain 1
Heavy chain of Fab fragment of Basiliximab Chains: A, C, H
Molecule details ›
Chains: A, C, H
Length: 215 amino acids
Theoretical weight: 23.14 KDa
Source organism: Mus musculus
Expression system: Escherichia coli
Structure domains: Immunoglobulins
Immunoglobulin kappa constant Chains: B, D, L
Molecule details ›
Chains: B, D, L
Length: 210 amino acids
Theoretical weight: 22.88 KDa
Source organism: Mus musculus
Expression system: Escherichia coli
  • Canonical: P01834 (Residues: 1-106; Coverage: 99%)
Gene name: IGKC
Sequence domains: Immunoglobulin C1-set domain
Structure domains: Immunoglobulins

Ligands and Environments

2 bound ligands:

No modified residues

Experiments and Validation Details

Entry percentile scores
X-ray source: SSRF BEAMLINE BL17U
Spacegroup: P6522
Unit cell:
a: 137.051Å b: 137.051Å c: 459.095Å
α: 90° β: 90° γ: 120°
R R work R free
0.217 0.215 0.262
Expression systems:
  • Spodoptera frugiperda
  • Escherichia coli