Escherichia coli CadB is capable of promiscuously transporting muropeptides and contributing to peptidoglycan recycling

• The bacterial peptidoglycan (PG) cell wall is remodeled during growth and division, releasing fragments called muropeptides. Muropeptides can be internalized and reused in a process called PG recycling. Escherichia coli is highly devoted to recycling muropeptides and is known to have at least two transporters, AmpG and OppBCDF, that import them into the cytoplasm. While studying mutants lacking AmpG, we unintentionally isolated mutations that led to the altered expression of a third transporter, CadB. CadB is normally upregulated under acidic pH conditions and is an antiporter for lysine and cadaverine. Here, we explored if CadB was altering PG recycling to assist in the absence of AmpG. Surprisingly, CadB overexpression was able to restore PG recycling when both AmpG and OppBCDF were absent. CadB was found to import freed PG peptides, a subpopulation of muropeptides, through a promiscuous activity. Altogether, our data support that CadB is a third transporter capable of contributing to PG recycling.

Ämnesord

NATURVETENSKAP  -- Biologi -- Mikrobiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Microbiology (hsv//eng)

Nyckelord

cell wall

muropeptides

peptidoglycan

peptidoglycan recycling

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)