Figure 1

Aberrant migration of Msp1 on SDS-PAGE compared to theoretical predictions. (A) SDS-PAGE analysis of LGG's secreted proteins present in spent culture supernatant after overnight growth in AOAC medium. The proteins in lane 1 correspond to the molecular mass standard (Candy Cane). Lane 2 corresponds to the secreted proteins of LGG WT. Arrows indicate the major secreted proteins of LGG. Msp1 was confirmed by Edman degradation and MS/MS to correspond to LGG_00324 (YP_003170070). Msp2 was confirmed by Edman degradation and MS/MS to correspond to LGG_00031 (YP_003169777). The gels are stained with Sypro^® Ruby. (B) Genomic context of the msp1 gene ( LGG_00324) . (C) Amino acid sequence of Msp1. The underlined amino acids indicate the signal peptide that is cleaved off after secretion. Additionally, the theoretical trypsin digest is depicted (indicated by ||). The theoretical mass and pI after cleavage of the signal peptide are respectively 6.06 and 46779 Da. Peptides that were experimentally identified by Edman degradation or MS/MS analysis are indicated in bold. As trypsin digestion yields long peptide fragments, this complicated the identification of multiple peptides. The truncated form of Msp1 which is expressed in the msp1 mutant CMPG10200 is indicated in between the triangles (▼).