Elucidating the lipopolysaccharide biosynthetic pathway in Myxococcus xanthus
Graduate Students Mini-Symposium
- Datum: 23.10.2017
- Uhrzeit: 13:50
- Vortragende(r): Maria Perez Burgos
- MPI, Dept. of Ecophysiology
- Ort: MPI for Terrestrial Microbiology
- Raum: Lecture hall
- Gastgeber: Prof. Dr. L. Søgaard-Andersen
- Kontakt: sogaard@mpi-marburg.mpg.de
Bacteria possess surface
polysaccharides that can interact with the environment and fulfill different
functions including mediating host/pathogen interactions as well as acting as a
first barrier to protect cells from desiccation stress, predation or
immunological reaction.
Cells of the rod-shaped,
Gram negative deltaproteobacterium Myxococcus xanthus can move by means
of two genetically distinct motility systems: T4P-dependent motility and
gliding motility. Exopolysaccharides and the O-antigen part of the
lipopolysaccharide (LPS) are essential for T4P-dependent motility in M.
xanthus, but little is known about the biosynthetic machineries, regulation
and composition of these different surface polysaccharides. Three different
machineries for biosynthesis of surface polysaccharides have been described in
other bacteria. Here, we identified genes for 15 proteins in M. xanthus with homology to proteins of the
Wzx-Wzy dependent pathway involved in surface polysaccharide synthesis as well
as two genes for proteins of an ABC transporter previously described to be
important for O-antigen transport. Genetic analyses of these 17 genes in combination
with measurements of EPS and LPS accumulation allowed us to elucidate in
details the biosynthetic pathway for LPS. Moreover, the overall layout of the
EPS pathway has been identified.