Identification of a dedicated recycling pathway for anhydro-N-acetylmuramic acid and N-acetylglucosamine derived from Escherichia coli cell wall murein.
Turnover and recycling of the cell wall murein represent a major metabolic pathway of Escherichia coli. It is known that E. coli efficiently reuses, i.e., recycles, its murein tripeptide, L-alanyl-gamma-D-glutamyl-meso-diaminopimelate, to form new murein. However, the question of whether the cells also recycle the amino sugar moieties of cell wall murein has remained unanswered. It is demonstrated here that E. coli recycles the N-acetylglucosamine present in cell wall murein degradation products for de novo murein and lipopolysaccharide synthesis. Furthermore, E. coli also recycles the anhydro-N-acetylmuramic acid moiety by first converting it into N-acetylglucosamine. Based on the results obtained by studying mutants unable to recycle amino sugars, the pathway for recycling is revealed.
Park
J T
JT
Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA. james.park@tufts.edu
D000117:Acetylglucosamine / Q000378:metabolism*; D000581:Amidohydrolases / Q000378:metabolism; D000606:Amino Sugars / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000096:biosynthesis; D008954:Models, Biological; D009112:Muramic Acids / Q000378:metabolism*; D010457:Peptidoglycan / Q000378:metabolism*
D000606:Amino Sugars; D008070:Lipopolysaccharides; D009112:Muramic Acids; D010457:Peptidoglycan; C430327:anhydro-N-acetylmuramic acid; D000581:Amidohydrolases; C018717:N-acetylglucosamine-6-phosphate deacetylase; D000117:Acetylglucosamine