The mycoplasma surface proteins MIB and MIP promote the dissociation of the antibody-antigen interaction

Pierre Nottelet, Laure Bataille, Geraldine Gourgues, Robin Anger, Carole Lartigue, Pascal Sirand-Pugnet, Esther Marza, Remi Fronzes, Yonathan Arfi
2021 Science Advances  
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 VH 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 VL and VH domains is twisted out of alignment, disrupting the antigen binding site. We also show that MIB-MIP has the ability
more » ... o 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.
doi:10.1126/sciadv.abf2403 pmid:33674316 pmcid:PMC7935358 fatcat:7qxswclywfennfehrchwigkcgi