Camelid nanobodies used as crystallization chaperones for different constructs of PorM, a component of the type IX secretion system from Porphyromonas gingivalis. Issue 5 (1st May 2017) - Duhoo, Yoan
Abstract : The structures of four nanobodies raised against the periplasmic domain of PorM were solved, and their interaction with their target was analysed. Diffracting crystals of two PorM constructs in complex with their specific nanobodies were obtained. Abstract : PorM is a membrane protein that is involved in the assembly of the type IX secretion system (T9SS) in Porphyromonas gingivalis, a major bacterial pathogen that is responsible for periodontal disease in humans. In the context of structural studies of PorM to better understand T9SS assembly, four camelid nanobodies were selected, produced and purified, and their specific interaction with the N‐terminal or C‐terminal part of the periplasmic domain of PorM was investigated. Diffracting crystals were also obtained, and the structures of the four nanobodies were solved by molecular replacement. Furthermore, two nanobodies were used as crystallization chaperones and turned out to be valuable tools in the structure‐determination process of the periplasmic domain of PorM.