The mycoplasma surface proteins MIB and MIP promote the dissociation of the antibody-antigen interaction
2021
Nottelet, Pierre | Bataille, Laure | Gourgues, Geraldine | Anger, Robin | Lartigue, Carole | Sirand-Pugnet, Pascal | Marza, Esther | Fronzes, Remi | Arfi, Yonathan | Institut Européen de Chimie et Biologie (IECB) ; Université de Bordeaux (UB)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS) | Biologie du fruit et pathologie (BFP) ; Université de Bordeaux (UB)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | ANR-17-CE35-0002,DACSyMy,Dissection moléculaire du système de clivage d'anticorps des mycoplasmes(2017)
International audience
显示更多 [+] 显示较少 [-]英语. Mycoplasma immunoglobulin binding (MIB) and mycoplasma immunoglobulin protease (MIP) are surface proteins found in the majority of mycoplasma species, acting sequentially to capture antibodies and cleave off their V H domains. Cryo-electron microscopy structures show how MIB and MIP bind to a Fab fragment in a "hug of death" mechanism. As a result, the orientation of the V L and V H domains is twisted out of alignment, disrupting the antigen binding site. We also show that MIB-MIP has the ability to promote the dissociation of the antibody-antigen complex. This system is functional in cells and protects mycoplasmas from antibody-mediated agglutination. These results highlight the key role of the MIB-MIP system in immunity evasion by mycoplasmas through an unprecedented mechanism, and open exciting perspectives to use these proteins as potential tools in the antibody field.
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