Figure 4

Structure model of LysEF-P10C and key residues. (A) Sequence alignment of the LysEF-P10C domain with the LysGH15 CHAP domain. The Cys-His-Glu-Asn quartets are indicated by filled blue squares. The 12-residue calcium-binding sites are indicated by a blue box, and positions 1, 3, 5, 7, and 12 (filled blue diamonds) are indicated by X, Y, Z, –X, and –Y, respectively. Schematic representations of the corresponding secondary structural elements are shown above the sequences. The alignment was generated using CLUSTAL W (http://www.ch.embnet.org/software/ClustalW.html). The figure was generated using ESPript (http://espript.ibcp.fr/ESPript/ESPript/index.php). (B) Structure model of the LysEF-P10C domain. The 3D structure model of the LysEF-P10C domain was created using Phyre2 (http://www.sbg.bio.ic.ac.uk/phyre2). (C) Detailed view of the putative catalytic and calcium-binding sites of LysEF-P10C. Cyan indicates the Cys-His-Asn triplet; green indicates the calcium-binding site. (D) Bactericidal activity of native LysEF-P10 and various mutants. The concentration of each protein was 20 µg/ml, and E. faecalis N10 was adjusted to 10⁸ CFU/ml. Values represent means ± SDs (n = 3).