Identification of a second binding site on the TRIM25 B30.2 domain

• Published in: Biochemical journal Vol. 475; no. 2; p. 429
• Main Authors: D'Cruz, Akshay A, Kershaw, Nadia J, Hayman, Thomas J, Linossi, Edmond M, Chiang, Jessica J, Wang, May K, Dagley, Laura F, Kolesnik, Tatiana B, Zhang, Jian-Guo, Masters, Seth L, Griffin, Michael D W, Gack, Michaela U, Murphy, James M, Nicola, Nicos A, Babon, Jeffrey J, Nicholson, Sandra E
• Format: Journal Article
• Language: English
• Published: England 31.01.2018
• Subjects: Amino Acid Sequence; Animals; B30.2-SPRY Domain - genetics; Binding Sites; Caspase Activation and Recruitment Domain - genetics; Cloning, Molecular; Crystallography, X-Ray; DEAD Box Protein 58 - chemistry; DEAD Box Protein 58 - genetics; DEAD Box Protein 58 - metabolism; Escherichia coli - genetics; Escherichia coli - metabolism; Genetic Vectors - chemistry; Genetic Vectors - metabolism; Glutathione Transferase - genetics; Glutathione Transferase - metabolism; HEK293 Cells; Histidine - genetics; Histidine - metabolism; Humans; Mice; Models, Molecular; Oligopeptides - genetics; Oligopeptides - metabolism; Protein Binding; Protein Conformation, alpha-Helical; Protein Conformation, beta-Strand; Protein Interaction Domains and Motifs; Receptors, Cytoplasmic and Nuclear - chemistry; Receptors, Cytoplasmic and Nuclear - genetics; Receptors, Cytoplasmic and Nuclear - metabolism; Receptors, Immunologic; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Recombinant Proteins - chemistry; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Sequence Deletion; RIG-I; TRIM25; B30.2; interferon; TRIM
• DOI: 10.1042/BCJ20170427

The etinoic acid- nducible ene- (RIG-I) receptor recognizes short 5'-di- and triphosphate base-paired viral RNA and is a critical mediator of the innate immune response against viruses such as influenza A, Ebola, HIV and hepatitis C. This response is reported to require an orchestrated interaction with the partite otif 25 (TRIM25) B30.2 protein-interaction domain. Here, we present a novel second RIG-I-binding interface on the TRIM25 B30.2 domain that interacts with CARD1 and CARD2 ( aspase ctivation and ecruitment omains) of RIG-I and is revealed by the removal of an N-terminal α-helix that mimics dimerization of the full-length protein. Further characterization of the TRIM25 coiled-coil and B30.2 regions indicated that the B30.2 domains move freely on a flexible tether, facilitating RIG-I CARD recruitment. The identification of a dual binding mode for the TRIM25 B30.2 domain is a first for the SPRY/B30.2 domain family and may be a feature of other SPRY/B30.2 family members.