Fig. 4.

Schematic diagrams of the putative domain structures of novel S. gordonii cell surface proteins. The two largest proteins, SGO_0707 (a) and SGO_1487 (b), shared structural features such as the LPXTG-containing anchor domain and tandem repeats with the large fibrillar protein CshA (c). Two smaller proteins, SGO_1247 (d) and SGO_0890 (e), contained the LPXTG anchor domains but lacked tandem repeats. The final novel protein SGO_0600 (f) contained a transmembrane sequence as well as a large extracellular domain of unknown function. Leader peptide (N-terminal consensus sequence for membrane insertion) (cross-hatched), unique domains (non-repetitive sequences) (white), repeat domains (tandemly repeated amino acid sequences of different lengths or degenerate tandem repeat domains) (lightly stippled), proline-rich domains (cross-hatched), domain with putative 5′-nucleotidase activity (white stippling on grey), domain with putative collagen-binding function (densely stippled), transmembrane domain (hydrophobic amino acid sequence) (cross-checked), and anchor domain (LPXTG-containing sequence) (white stippling on black).