posted on 2023-01-09, 16:08authored byDaniele Di Bari, Stepan Timr, Marianne Guiral, Marie-Thérèse Giudici-Orticoni, Tilo Seydel, Christian Beck, Caterina Petrillo, Philippe Derreumaux, Simone Melchionna, Fabio Sterpone, Judith Peters, Alessandro Paciaroni
Temperature variations have a big impact on bacterial
metabolism
and death, yet an exhaustive molecular picture of these processes
is still missing. For instance, whether thermal death is determined
by the deterioration of the whole or a specific part of the proteome
is hotly debated. Here, by monitoring the proteome dynamics of E. coli, we clearly show that only a minor fraction of the
proteome unfolds at the cell death. First, we prove that the dynamical
state of the E. coli proteome is an excellent proxy
for temperature-dependent bacterial metabolism and death. The proteome
diffusive dynamics peaks at about the bacterial optimal growth temperature,
then a dramatic dynamical slowdown is observed that starts just below
the cell’s death temperature. Next, we show that this slowdown
is caused by the unfolding of just a small fraction of proteins that
establish an entangling interprotein network, dominated by hydrophobic
interactions, across the cytoplasm. Finally, the deduced progress
of the proteome unfolding and its diffusive dynamics are both key
to correctly reproduce the E. coli growth rate.