Figure 3.

Plot of the 851 DD-peptidase/β-lactamase–like superfamily (CATH 3.40.710.10) sequences.

Each dot represents a sequence identified by the profile with its HMM bit score result. The HMM bit score reflects whether the sequence is a better match to the profile model (positive score) or the null model of nonhomologous sequences (negative score). The dashed lines in the graphs indicate the established HMM bit score threshold for each profile. X: numbered sequence order, Y: HMM bit score. Red circle: 295 sequences from BL class SA, green circle: 177 sequences from BL class SC, brown circle: 103 sequences from BL class SD, blue triangle: proteins inserted within the BL clades that are not functionally characterized as BLs, and black inverted triangle: other non-BL sequences from DD-peptidase/β-lactamase–like superfamily. Arrows indicate particular proteins quoted in the text; BL: Beta-lactamase.