Abstract
Gram-negative bacteria possess specialized biogenesis machineries that facilitate the export of amyloid subunits, the fibers of which are key components of their biofilm matrix. The secretion of bacterial functional amyloid requires a specialized outer-membrane protein channel through which unfolded amyloid substrates are translocated. We previously reported the crystal structure of the membrane-spanning domain of the amyloid subunit transporter FapF from Pseudomonas. However, the structure of the periplasmic domain, which is essential for amyloid transport, is yet to be determined. Here, we present the crystal structure of the N-terminal periplasmic domain at 1.8-Å resolution. This domain forms a novel asymmetric trimeric coiled coil that possesses a single buried tyrosine residue as well as an extensive hydrogen-bonding network within a glutamine layer. This new structural insight allows us to understand this newly described functional amyloid secretion system in greater detail.
Highlights
The formation and deposition of the amyloid state of proteins, amyloidogenesis, is a major cause of degenerative human disorders [1]
Gram-negative bacteria possess specialized biogenesis machineries that facilitate the export of amyloid subunits, the fibers of which are key components of their biofilm matrix
To utilize amyloid fibers for functional purposes without the cytotoxic effects, bacteria have evolved highly efficient pathways to transport amyloidogenic polypeptides across cells and membranes allowing for their assembly at the correct time and place
Summary
The formation and deposition of the amyloid state of proteins, amyloidogenesis, is a major cause of degenerative human disorders [1]. We previously reported the crystal structure of the membrane-spanning domain of the amyloid subunit transporter FapF from Pseudomonas. This domain forms a novel asymmetric trimeric coiled coil that possesses a single buried tyrosine residue as well as an extensive hydrogen-bonding network within a glutamine layer.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
