Fig. 4: LDTGo catalyzes D,L-amino acid exchange reaction. | Nature Communications

Fig. 4: LDTGo catalyzes D,L-amino acid exchange reaction.

From: A distinctive family of L,D-transpeptidases catalyzing L-Ala-mDAP crosslinks in Alpha- and Betaproteobacteria

Fig. 4

A Scheme of the amino acid exchange reaction performed by LD3,3-TPases with non-canonical (NCDAA. e.g., D-Met) and Fluorescent (FDAA, e.g., HADA) D-amino acids. B Phase contrast (PC) and fluorescence microscopy of G. oxydans wild-type, ΔldtGo mutant and ldtGo::ycbBEc allelic exchange cells labeled with HADA. Scale bar: 2 µm. Microscopy images shown are representative of three biological replicates. C Zoom-in of the UV muropeptide profiles of the same strains indicated in panel (B) cultured with 10 mM of D-Met or without (control). D Zoom-in of the UV muropeptide profile of G. oxydans wild-type highlighting the dipeptide muropeptides (M2X, in red) including those exhibiting amino acid exchange (M2Phe and M2Trp), and the LD1,3-crosslinked muropeptides in green. The MS extracted ion chromatogram (XIC) traces are shown for the indicated M2X muropeptide species. E UV muropeptide profile of G. oxydans (Go) wild-type (WT) and ΔldtGo mutant strains cultured without (control) or with 10 mM of L-Phe or D-Phe (left panel). Middle panel: zoom-in of the UV muropeptide profile where the M2Phe muropeptide elutes. Right panel: MS extracted ion chromatogram (XIC) trace of M2Phe.

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