Figure 1.

Schematic of IsdB sequence features. Amino acids are numbered according to the S. aureus N315 IsdB sequence (NP_374246). The black bar near the N-terminus signifies the signal sequence, which directs the protein to be secreted onto the surface. The white bar near the C-terminus signifies the LPQTG sortase signal, which directs the protein to be covalently anchored to the peptidoglycan by sortase A. The two NEAT domains are shown in different shades of gray to indicate their dissimilar pairwise sequence identity (12%). The mature protein on the staphylococcal surface encompasses Ala41–Thr613.