Peptidoglycan biosynthesis and remodeling revisited

Campylobacter jejuni 11168H Exposed to Penicillin Forms Persister Cells and Cells With Altered Redox Protein Activity

“…The upregulation of this efflux pump has also been reported after phage infection (Sacher et al, 2018). Our proteome analysis also highlighted MurG (Cj1039) to be over-produced, which catalysis the final intracellular step of peptidoglycan synthesis (Shaku et al, 2020), indicating a possible role of this enzyme in restoring cell wall integrity after exposure to penicillin G. The majority of the proteins with increased abundance were associated with translation and amino acid metabolism and transport.…”

Acinetobacter baumannii Can Survive with an Outer Membrane Lacking Lipooligosaccharide Due to Structural Support from Elongasome Peptidoglycan Synthesis

“…Peptidoglycan synthesis is a major target of antibiotic treatment, and it is critical that we understand these essential processes for multidrug-resistant pathogens like A. baumannii . In many model Gram-negative bacteria, PBP1A is dispersed along the periphery of the cell and thought to synthesize peptidoglycan in patches where needed ( 15 ), whereas PBP1B localizes and synthesizes peptidoglycan at the poles ( 15 ). The loss of PBP1A or PBP1B can be tolerated in E. coli , but deletion of both is synthetically lethal, indicating that despite different localizations, they are functionally redundant ( 15 ).…”

“…The peptidoglycan wall plays a major role in resisting osmotic and mechanical stresses and is critical for cell shape and rigidity ( 12 – 14 ). Peptidoglycan is a sturdy mesh built by glycosyltransferases that polymerize a polysaccharide backbone and transpeptidases that cross-link short peptide bridges between strands ( 15 ). Building and growing the structure require coordination between multienzymatic complexes of cytoskeletal proteins and synthetic and degradative enzymes.…”

“…The elongasome and divisome are complexes that include s hape, e longation, d ivision, and s porulation (SEDS)-family glycosyltransferases, class B penicillin binding protein transpeptidases, and other subunits, which synthesize peptidoglycan along the axis/length of the cell and at septa, respectively ( 16 – 20 ). Finally, class A penicillin binding proteins contain both glycosyltransferase and transpeptidase activities and can synthesize peptidoglycan either axially or septally ( 15 ).…”

“…Tn-seq identified that every member of the elongasome and ElsL were likely essential during LOS deficiency. Muropeptide and genetic analysis of mutants lacking ElsL suggested that this protein may instead be a cytoplasmic l , d -carboxypeptidase, involved in recycling of peptidoglycan fragments ( 15 ). ElsL and the elongasome were confirmed to be essential for the growth and viability of LOS-deficient mutants.…”