The fructan syndrome in the tree of life: from structure to function

Fructans, naturally occurring fructose based polysaccharides, can act
as native immunity triggers, both in humans and animals (oral intake:
prebiotics) and in plants (leaf spraying: defense priming). They are
produced by fructosyl transferase enzymes belonging to the GHJ
class. Through genome sequencing and phylogenetic analyses, we
will further explore the GHJ class in the tree of life, with special focus
on novel enzymes with unique substrate specificities in plants and
salt loving Haloarchaea. Crystallization and 3D structure analysis will
allow a holistic approach on structure-function relationships
throughout the tree of life. These unique insights will be used to
resolve long-standing central questions: which molecular
determinants are controlling (i) the linkage-type during synthesis
(inulin versus levan) and degradation and (ii) the mode of action
(endo versus exo) during degradation? On turn, these insights will
pave the way to rational enzyme design, creating enzymes that have
not been characterized from natural resources (e.g. fungal
endolevanase), but hold great promise for the production of superior
prebiotics, immunomodulators, antioxidants or priming compounds,
useful to decrease our dependency on toxic agrochemicals and
antibiotics in future sustainable societies.