Figure 3

The secretome selection diagram. The key selection steps are boxed. Rounded squares represent E. coli cells and rounded rectangles represent recombinant phagemids replicating as plasmids inside the cells. pIII is shown as a red rectangle on the plasmid backbone. Inserts are represented as rectangles of various colors and lengths. Small orange ovals represent the signal sequences. The pipe-cleaner-like shapes represent phagemid particles obtained after infection of the library with the helper phage VCSM13d3. The elongated rectangles along the axes represent packaged DNA of the library clones. The top ends of the phagemid particles contain pVII and pIX proteins. The bottom ends of the phagemid particles are either open (signal sequence-negative clones) or capped by protein-pIII fusions (signal sequence-positive clones; popsicle shapes). Sarcosyl^S, phagemid particles sensitive to sarcosyl; sarcosyl^R, the secretome protein-displaying phagemid particles, resistant to sarcosyl. Numbers in brackets refer to data obtained in the L. rhamnosus HN001 secretome selection experiment in this work. Steps denoted in grey indicate downstream applications of the secretome library.