RCSB PDB - 3QD6: Crystal structure of the CD40 and CD154 (CD40L) complex (original) (raw)
Crystallographic and mutational analysis of the CD40-CD154 complex and its implications for receptor activation
[An, H.-J.](/search?q=citation.rcsb%5Fauthors:An, H.-J.), [Kim, Y.J.](/search?q=citation.rcsb%5Fauthors:Kim, Y.J.), [Song, D.H.](/search?q=citation.rcsb%5Fauthors:Song, D.H.), [Park, B.S.](/search?q=citation.rcsb%5Fauthors:Park, B.S.), [Kim, H.M.](/search?q=citation.rcsb%5Fauthors:Kim, H.M.), [Lee, J.D.](/search?q=citation.rcsb%5Fauthors:Lee, J.D.), [Paik, S.-G.](/search?q=citation.rcsb%5Fauthors:Paik, S.-G.), [Lee, J.-O.](/search?q=citation.rcsb%5Fauthors:Lee, J.-O.), [Lee, H.](/search?q=citation.rcsb%5Fauthors:Lee, H.)
(2011) J Biol Chem 286: 11226-11235
PubMed Abstract:
CD40 is a tumor necrosis factor receptor (TNFR) family protein that plays an important role in B cell development. CD154/CD40L is the physiological ligand of CD40. We have determined the crystal structure of the CD40-CD154 complex at 3.5 Å resolution. The binding site of CD40 is located in a crevice formed between two CD154 subunits. Charge complementarity plays a critical role in the CD40-CD154 interaction. Some of the missense mutations found in hereditary hyper-IgM syndrome can be mapped to the CD40-CD154 interface. The CD40 interaction area of one of the CD154 subunits is twice as large as that of the other subunit forming the binding crevice. This is because cysteine-rich domain 3 (CRD3) of CD40 has a disulfide bridge in an unusual position that alters the direction of the ladder-like structure of CD40. The Ser(132) loop of CD154 is not involved in CD40 binding but its substitution significantly reduces p38- and ERK-dependent signaling by CD40, whereas JNK-dependent signaling is not affected. These findings suggest that ligand-induced di- or trimerization is necessary but not sufficient for complete activation of CD40.
Organizational Affiliation:
Department of Biology, College of Bioscience & Biotechnology, Chungnam National University, Daejon, Korea.