Figure 7.
Peptides from the N-terminal portion of conserved hypothetical protein SO_3842. The peptide breakage before the starred residue is produced when the signal peptide is cleaved and degraded. The other nontryptic peptides are properly contained in observed tryptic peptides and are most likely generated by post-digestion breakup. The N-terminal “ladder” observed for the tryptic peptide QMSIGTDTLLQIK is a likely result of aminopeptidase-driven trimming or in-source fragmentation.
