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FhaC takes a bow to FHA in the two‐partner do‐si‐do
Author(s) -
Noinaj Nicholas,
Buchanan Susan K.
Publication year - 2014
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.12627
Subject(s) - secretion , biology , transporter , helix (gastropod) , virulence , order (exchange) , virulence factor , transport protein , biophysics , microbiology and biotechnology , biochemistry , gene , ecology , finance , snail , economics
Summary FhaC is an outer membrane transporter from B ordetella pertussis belonging to the t wo‐ p artner s ecretion ( TPS ) pathway with its primary role being the secretion of the virulence factor f ilamentous h aem a gglutinin ( FHA ). FhaC serves as a model transporter of the TPS pathway and significant work has been done to characterize the role of FhaC in FHA secretion. Recent studies characterized interactions between FHA and the POTRA domains of FhaC , suggesting that secretion may involve a successive translocation mechanism mediated by β‐augmentation and/or electrostatic interactions. Moreover, it was also shown that reconstituted FhaC is necessary and sufficient to transport FHA into proteoliposomes. While the crystal structure of FhaC clearly suggests a role in transport, the putative transport pore is plugged by an N ‐terminal α‐helix ( H 1 helix) that occludes access by FHA . Therefore, it has been proposed that the H 1 helix must be expelled from the pore in order for secretion of FHA to occur. However, this has yet to be shown experimentally. Guérin et al . (2014) report the first direct experimental evidence to show that the FhaC H 1 helix is quite dynamic and exchanges between closed and open states upon interaction with FHA .