| Structural highlights
Function
C562_ECOLX Electron-transport protein of unknown function.AMPG_ECOLI Permease involved in cell wall peptidoglycan recycling (PubMed:12426329, PubMed:8878601). Transports, from the periplasm into the cytoplasm, the disaccharide N-acetylglucosaminyl-beta-1,4-anhydro-N-acetylmuramic acid (GlcNAc-anhMurNAc) and GlcNAc-anhMurNAc-peptides (PubMed:12426329). Transport is dependent on the proton motive force (PubMed:12426329). AmpG is also involved in beta-lactamase induction (PubMed:7773404).[1] [2] [3]
Publication Abstract from PubMed
Bacteria invest significant resources into the continuous creation and tailoring of their essential protective peptidoglycan (PG) cell wall. Several soluble PG biosynthesis products in the periplasm are transported to the cytosol for recycling, leading to enhanced bacterial fitness. GlcNAc-1,6-anhydroMurNAc and peptide variants are transported by the essential major facilitator superfamily importer AmpG in Gram-negative pathogens including Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa. Accumulation of GlcNAc-1,6-anhydroMurNAc-pentapeptides also results from beta-lactam antibiotic induced cell wall damage. In some species, these products upregulate the beta-lactamase AmpC, which hydrolyzes beta-lactams to allow for bacterial survival and drug-resistant infections. Here, we have used cryo-electron microscopy and chemical synthesis of substrates in an integrated structural, biochemical, and cellular analysis of AmpG. We show how AmpG accommodates the large GlcNAc-1,6-anhydroMurNAc peptides, including a unique hydrophobic vestibule to the substrate binding cavity, and characterize residues involved in binding that inform the mechanism of proton-mediated transport.
, PMID:39548104[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Cheng Q, Park JT. Substrate specificity of the AmpG permease required for recycling of cell wall anhydro-muropeptides. J Bacteriol. 2002 Dec;184(23):6434-6. PMID:12426329 doi:10.1128/JB.184.23.6434-6436.2002
- ↑ Schmidt H, Korfmann G, Barth H, Martin HH. The signal transducer encoded by ampG is essential for induction of chromosomal AmpC beta-lactamase in Escherichia coli by beta-lactam antibiotics and 'unspecific' inducers. Microbiology (Reading). 1995 May;141 ( Pt 5):1085-1092. PMID:7773404 doi:10.1099/13500872-141-5-1085
- ↑ Dietz H, Pfeifle D, Wiedemann B. Location of N-acetylmuramyl-L-alanyl-D-glutamylmesodiaminopimelic acid, presumed signal molecule for beta-lactamase induction, in the bacterial cell. Antimicrob Agents Chemother. 1996 Sep;40(9):2173-7. PMID:8878601 doi:10.1128/AAC.40.9.2173
- ↑ Sverak HE, Yaeger LN, Worrall LJ, Vacariu CM, Glenwright AJ, Vuckovic M, Al Azawi ZD, Lamers RP, Marko VA, Skorupski C, Soni AS, Tanner ME, Burrows LL, Strynadka NC. Cryo-EM characterization of the anydromuropeptide permease AmpG central to bacterial fitness and β-lactam antibiotic resistance. Nat Commun. 2024 Nov 16;15(1):9936. PMID:39548104 doi:10.1038/s41467-024-54219-9
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