2Z3Q

Crystal structure of the IL-15/IL-15Ra complex

Summary for 2Z3Q

• Entry DOI: 10.2210/pdb2z3q/pdb
• Related: 2Z3R
• Descriptor: Interleukin-15, Interleukin-15 receptor alpha chain (3 entities in total)
• Functional Keywords: protein-protein complex, cytokine-cytokine receptor complex, cytokine/cytokine receptor
• Biological source: Homo sapiens (human); More
• Cellular location: Isoform IL15-S48AA: Secreted. Isoform IL15-S21AA: Cytoplasm: P40933; Membrane; Single-pass type I membrane protein. Isoform 5: Endoplasmic reticulum membrane; Single-pass type I membrane protein. Isoform 6: Endoplasmic reticulum membrane; Single-pass type I membrane protein. Isoform 7: Endoplasmic reticulum membrane; Single-pass type I membrane protein. Isoform 8: Endoplasmic reticulum membrane; Single-pass type I membrane protein. Soluble interleukin-15 receptor subunit alpha: Secreted, extracellular space: Q13261
• Total number of polymer chains: 4
• Total formula weight: 49508.30

Authors

Chirifu, M.,Yamagata, Y.,Davis, S.J.,Ikemizu, S. (deposition date: 2007-06-05, release date: 2007-09-04, Last modification date: 2024-10-30)

Primary citation

Chirifu, M.,Hayashi, C.,Nakamura, T.,Toma, S.,Shuto, T.,Kai, H.,Yamagata, Y.,Davis, S.J.,Ikemizu, S.
Crystal structure of the IL-15-IL-15Ralpha complex, a cytokine-receptor unit presented in trans
Nat.Immunol., 8:1001-1007, 2007

PubMed Abstract: Interleukin 15 (IL-15) and IL-2, which promote the survival of memory CD8(+) T cells and regulatory T cells, respectively, bind receptor complexes that share beta- and gamma-signaling subunits. Receptor specificity is provided by unique, nonsignaling alpha-subunits. Whereas IL-2 receptor-alpha (IL-2Ralpha) is expressed together in cis with the beta- and gamma-subunits on T cells and B cells, IL-15Ralpha is expressed in trans on antigen-presenting cells. Here we present a 1.85-A crystal structure of the human IL-15-IL-15Ralpha complex. The structure provides insight into the molecular basis of the specificity of cytokine recognition and emphasizes the importance of water in generating this very high-affinity complex. Despite very low IL-15-IL-2 sequence homology and distinct receptor architecture, the topologies of the IL-15-IL-15Ralpha and IL-2-IL-2Ralpha complexes are very similar. Our data raise the possibility that IL-2, like IL-15, might be capable of being presented in trans in the context of its unique receptor alpha-chain.

PubMed: 17643103
DOI: 10.1038/ni1492

Experimental method

X-RAY DIFFRACTION (1.85 Å)