The role of N-actylglucosaminyl-1,6 anhydro N-acetylmuramyl-L-alanyl-D-glutamyl-meso-diaminopimelic acid-D-alanine for the induction of beta-lactamase in Enterobacter cloacae.
The mechanism of beta-lactamase induction in Enterobacter cloacae which is linked to the peptidoglycan recycling, was investigated by HPLC analysis of cell wall fragments in genetically defined cells. It is demonstrated here that the transmembrane protein AmpG transports not only the precursor muropeptide of M-tripeptide (N-acetylmuramyl-L-alanyl-D-glutamyl-meso-diaminopimelic acid), the D-tripeptide (N-actylglucosaminyl-1,6 anhydro N-acetylmuramyl-L-alanyl-D-glutamyl-meso-diaminopimelic acid), but also that of M-tetra-peptide (N-acetylmuramyl-L-alanyl-D-glutamyl-meso-diaminopimelic acid-D-alanine), the D-tetrapeptide (N-actylglucosaminyl-1,6 anhydro N-acetylmuramyl-L-alanyl-D-glutamyl-meso-diaminopimelic acid-D-alanine), into the cytoplasm. These findings indicate that probably also M-tetrapeptide and D-tetrapeptide are signal muropeptides for beta-lactamase induction. In fact, D-tetrapeptide, not D-tripeptide, increases upon imipenem treatment.
Dietz
H
H
University of Bonn, Germany.
Wiedemann
B
B
D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000031:analogs & derivatives* / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D016972:Enterobacter cloacae / Q000201:enzymology*; D004790:Enzyme Induction; D008565:Membrane Proteins / Q000378:metabolism*; D026901:Membrane Transport Proteins; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000378:metabolism; D010457:Peptidoglycan; D001618:beta-Lactamases / Q000096:biosynthesis*
C084284:AmpG protein, Bacteria; D001426:Bacterial Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D010457:Peptidoglycan; D000119:Acetylmuramyl-Alanyl-Isoglutamine; C032972:peptidoglycan pentapeptide-mDap3; C062460:AmpD protein, Bacteria; D009238:N-Acetylmuramoyl-L-alanine Amidase; D001618:beta-Lactamases