Figure 1.

Domain organization and sequence features of SRR proteins. a, diagram of SRR protein domain architecture, truncated variant GspB736FLAG, and GspB variant D (GspBvD) domains. b, alignment of SRR protein signal sequences of representative Streptococcus and Staphylococcus species. S. gordonii¹ is strain M99, S. gordonii² is strain Challis, S. agalactiae¹ is strain COH31, and S. agalactiae² is strain COH1. Shown are species, protein name, signal sequences, and N-region net charge. Red, residues of the conserved polybasic motif. Blue, conserved glycine residues. Highlighted are the predicted N-region, hydrophobic core, and C-regions of the signal peptide sequences.