1XU1

The crystal structure of APRIL bound to TACI

Summary for 1XU1

• Entry DOI: 10.2210/pdb1xu1/pdb
• Related: 1u5x 1u5y 1u5z 1XU2 1XUT
• Descriptor: Tumor necrosis factor ligand superfamily member 13, Tumor necrosis factor receptor superfamily member 13B, NICKEL (II) ION, ... (4 entities in total)
• Functional Keywords: tnfsf, cytokine, crd, receptor, jelly-roll, cysteine-rich, hormone-growth factor receptor complex, hormone/growth factor receptor
• Biological source: Mus musculus (house mouse); More
• Cellular location: Secreted (By similarity): Q9D777; Membrane; Single-pass type III membrane protein: O14836
• Total number of polymer chains: 6
• Total formula weight: 61410.49

Authors

Hymowitz, S.G.,Patel, D.R.,Wallweber, H.J.A.,Runyon, S.,Yan, M.,Yin, J.,Shriver, S.K.,Gordon, N.C.,Pan, B.,Skelton, N.J.,Kelley, R.F.,Starovasnik, M.A. (deposition date: 2004-10-25, release date: 2004-11-09, Last modification date: 2023-08-23)

Primary citation

Hymowitz, S.G.,Patel, D.R.,Wallweber, H.J.A.,Runyon, S.,Yan, M.,Yin, J.,Shriver, S.K.,Gordon, N.C.,Pan, B.,Skelton, N.J.,Kelley, R.F.,Starovasnik, M.A.
Structures of APRIL-receptor complexes: Like BCMA, TACI employs only a single cysteine-rich domain for high-affinity ligand binding
J.Biol.Chem., 280:7218-7227, 2005

PubMed Abstract: TACI is a member of the tumor necrosis factor receptor superfamily and serves as a key regulator of B cell function. TACI binds two ligands, APRIL and BAFF, with high affinity and contains two cysteine-rich domains (CRDs) in its extracellular region; in contrast, BCMA and BR3, the other known high affinity receptors for APRIL and BAFF, respectively, contain only a single or partial CRD. However, another form of TACI exists wherein the N-terminal CRD is removed by alternative splicing. We find that this shorter form is capable of ligand-induced cell signaling and that the second CRD alone (TACI_d2) contains full affinity for both ligands. Furthermore, we report the solution structure and alanine-scanning mutagenesis of TACI_d2 along with co-crystal structures of APRIL.TACI_d2 and APRIL.BCMA complexes that together reveal the mechanism by which TACI engages high affinity ligand binding through a single CRD, and we highlight sources of ligand-receptor specificity within the APRIL/BAFF system.

PubMed: 15542592
DOI: 10.1074/jbc.M411714200

Experimental method

X-RAY DIFFRACTION (1.9 Å)