4. Effects of acetylation on bacteria metabolism
To survive, and compete in their natural habitats, bacteria must be able
to respond to environmental disturbances or nutrient availability
fluctuations by adapting their metabolism. A quick response mechanism is
through the regulation of the activity of metabolic enzymes, which can
be controlled in three different aspects: the amount of enzyme, the
catalytic activity, and the accessibility of substrates (Figure 3)
(Xiong & Guan, 2012). Reversible post-translational modification, such
as lysine acetylation, may be involved in at least one of these aspects.
Acetylation regulates the metabolic enzyme amount by promoting the
assembly of functional multimeric structures that bind to the proteasome
for the degradation of proteins or by targeting the substrate for
ubiquitylation and proteasome-dependent degradation (Liu et al., 2021;
Xiong & Guan, 2012). The enzymatic activity regulation is related to
changes in the physical-chemical properties of the catalytic pocket.
Several acetylated proteins have found a highly conserved lysine residue
within the catalytic active site. The acetylation on this residue
neutralizes its positive charge and increases its size, which causes a
conformational change in the active site (Kim et al., 2006; Nakayasu et
al., 2017). Also, acetylation can regulate substrate accessibility by
hindering substrate entry into the active site (Figure 3).