Figure 1.
The monomer unit of the peptidoglycan structure.
The disaccharide moiety is composed of the amino sugars N-acetylglucosamine (GlcNAc) and N-acetylmuramic (MurNAc) linked via a β-1,4 glycosidic bond. The amino acid at position 3 of the stem peptide is meso-diaminopimelic acid (R = COOH) in most Gram-negative bacteria and l-lysine (R = H) in most Gram-positive bacteria.
Figure 2.
Scanning electron microscopy of V. spinosum DSM 4136T.
The white arrows show the wart-like prosthecae (WLP) and the white bar depicts a tube-like prosthecae (TLP). The picture was taken at 25 K magnification. The scale bar is 1 µm.
Table 1.
List of genes involved in PG metabolism of V. spinosum DSM 4136T.
Figure 3.
Expression and purification of recombinant MurEVs using His-tag affinity chromatography.
Lane (1) protein makers (kDa); Lane (2) 10 µg of soluble protein from uninduced cells; Lane (3) 10 µg of soluble protein from induced cells; Lane (4) 1 µg of purified recombinant MurEVs. The proteins were resolved on 10% (w/v) acrylamide gel and were stained using Coomassie blue.
Table 2.
Specificity of MurEVs for the amino acid substrate.
Figure 4.
(a) The homology model of MurEVs highlighting domains A (grey), B (violet) and C (pink). (b) Shows the structure model of MurEVs bound to UDP-MurNAc-tripeptide (UMT) product (yellow). (c) Active site residue hypothesized to bind to UMT product is shown in red. The structure has been rotated 90° on the right panel for the better viewing of the binding pocket. (d) Cross eye stereo view showing the interaction between amino acid residues of the binding site and UMT product.
Figure 5.
Multiple amino acid sequence alignment of five representative sequences of MurE.
The residues that are predicted to be involved in binding in the active site are marked with a star below the sequence. The sequence identity score against MurE from V. spinosum was: C. trachomatis, 37%; E. coli, 35%; P. carotovorum, 36%; and M. tuberculosis. The multiple amino acid sequence alignment figure was generated using the ESPript 2.2 server (http://espript.ibcp.fr/ESPript/cgi-bin/ESPript.cgi).
Table 3.
Analysis of crude and purified PG from V. spinosum DSM 4136T.