PT  - JOURNAL ARTICLE
AU  - Michael C. Gilmore
AU  - Felipe Cava
TI  - Peptidoglycan recycling mediated by an ABC transporter in the plant pathogen <em>Agrobacterium tumefaciens</em>
AID  - 10.1101/2022.07.15.499691
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2022.07.15.499691
4099  - http://biorxiv.org/content/early/2022/08/03/2022.07.15.499691.short
4100  - http://biorxiv.org/content/early/2022/08/03/2022.07.15.499691.full
AB  - During growth and division, the bacterial cell wall peptidoglycan (PG) is remodelled, resulting in the liberation of PG muropeptides which are typically reinternalized and recycled. Bacteria belonging to the Rhizobiales and Rhodobacterales orders of the Alphaproteobacteria lack the canonical muropeptide transporter AmpG, despite having other key PG recycling enzymes. Here, we show that an alternative transporter, YejBEF-YepA, takes over this role in the Rhizobiales phytopathogen Agrobacterium tumefaciens. Muropeptide import by YejBEF-YepA governs expression of the β-lactamase AmpC in A. tumefaciens, contributing to β-lactam resistance. However, we show that the absence of YejBEF-YepA causes severe cell wall defects that go far beyond lowered AmpC activity. Thus, contrary to previously established Gram-negative models, PG recycling is vital for cell wall integrity in A. tumefaciens. YepA is widespread in the Rhizobiales and Rhodobacterales, suggesting that YejBEF-YepA-mediated PG recycling could represent an important but overlooked aspect of cell wall biology in these bacteria.Competing Interest StatementThe authors have declared no competing interest.