A Unique Human Mycoplasma Protein that Generically Blocks Antigen-Antibody Union

• Published in: Science (American Association for the Advancement of Science) Vol. 343; no. 6171; pp. 656 - 661
• Main Authors: Grover, Rajesh K., Zhu, Xueyong, Nieusma, Travis, Jones, Teresa, Boreo, Isabel, MacLeod, Amanda S., Mark, Adam, Niessen, Sherry, Kim, Helen J., Kong, Leopold, Assad-Garcia, Nacyra, Kwon, Keehwan, Chesi, Marta, Smider, Vaughn V., Salomon, Daniel R., Jelinek, Diane F., Kyle, Robert A., Pyles, Richard B., Glass, John I., Ward, Andrew B., Wilson, Ian A., Lerner, Richard A.
• Format: Journal Article
• Language: English
• Published: 07.02.2014
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1246135

We report the discovery and crystal structure of a human mycoplasma protein, Protein M, which binds with high affinity to antibodies, predominantly through attachment to the variable region of the κ and λ light chains. Protein M broadly blocks antibody-antigen union and its mechanism of inhibition is of considerable interest because, as a diversity system, the binding mode of each antibody is different. Protein M thus appears to function by a mechanism that is independent of the sequences of members of the extensive antibody repertoire. By anchoring to conserved regions of the antibody light chains, Protein M is in a position to extend its large C-terminal domain over the antibody combining site and block entrance to macromolecular antigens.