Figure 3. Key features and putative functional domains of the Bdr proteins. The schematic depicts a prototype Bdr protein with the characteristics of each domain indicated. The abbreviation, ID%, is for percentage amino acid identity at either the inter- or intra-family level as indicated in the figure. Standard amino acid abbreviations are used in the figure to denote the conserved C-terminal lysine (K) or asparagine (N) residues, which are thought to be exposed in the periplasm and the cytoplasmically located core tripeptide of the repeat motif (lysine-isoleucine-aspartic acid; KID).