5WI8

Crystal structure of murine 4-1BB from HEK293T cells in P21 space group

Summary for 5WI8

• Entry DOI: 10.2210/pdb5wi8/pdb
• Descriptor: Tumor necrosis factor receptor superfamily member 9, beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[alpha-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranose, alpha-D-mannopyranose-(1-6)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[alpha-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranose, ... (8 entities in total)
• Functional Keywords: tumor necrosis factor, apoptosis, immune system
• Biological source: Mus musculus (Mouse)
• Total number of polymer chains: 4
• Total formula weight: 67393.02

Authors

Zajonc, D.M.,Bitra, A. (deposition date: 2017-07-18, release date: 2017-12-20, Last modification date: 2024-10-16)

Primary citation

Bitra, A.,Doukov, T.,Wang, J.,Picarda, G.,Benedict, C.A.,Croft, M.,Zajonc, D.M.
Crystal structure of murine 4-1BB and its interaction with 4-1BBL support a role for galectin-9 in 4-1BB signaling.
J. Biol. Chem., 293:1317-1329, 2018

PubMed Abstract: 4-1BB (CD137) is a TNF receptor superfamily (TNFRSF) member that is thought to undergo receptor trimerization upon binding to its trimeric TNF superfamily ligand (4-1BBL) to stimulate immune responses. 4-1BB also can bind to the tandem repeat-type lectin galectin-9 (Gal-9), and signaling through mouse (m)4-1BB is reduced in galectin-9 (Gal-9)-deficient mice, suggesting a pivotal role of Gal-9 in m4-1BB activation. Here, using sulfur-SAD phasing, we determined the crystal structure of m4-1BB to 2.2-Å resolution. We found that similar to other TNFRSFs, m4-1BB has four cysteine-rich domains (CRDs). However, the organization of CRD1 and the orientation of CRD3 and CRD4 with respect to CRD2 in the m4-1BB structure distinctly differed from those of other TNFRSFs. Moreover, we mapped two Asn residues within CRD4 that are -linked glycosylated and mediate m4-1BB binding to Gal-9. Kinetics studies of m4-1BB disclosed a very tight nanomolar binding affinity to m4-1BBL with an unexpectedly strong avidity effect. Both N- and C-terminal domains of Gal-9 bound m4-1BB, but with lower affinity compared with m4-1BBL. Although the TNF homology domain (THD) of human (h)4-1BBL forms non-covalent trimers, we found that m4-1BBL formed a covalent dimer via 2 cysteines absent in h4-1BBL. As multimerization and clustering is a prerequisite for TNFR intracellular signaling, and as m4-1BBL can only recruit two m4-1BB monomers, we hypothesize that m4-1BBL and Gal-9 act together to aid aggregation of m4-1BB monomers to efficiently initiate m4-1BB signaling.

PubMed: 29242193
DOI: 10.1074/jbc.M117.814905

Experimental method

X-RAY DIFFRACTION (2.95 Å)