Figure 1. Schematic of the current models for co-translational protein targeting by the SRP pathway.

Targeting via FtsY molecules that are pre-bound and activated at the membrane is shown on the lower left (shaded in blue); the alternative targeting route via FtsY molecules in solution is shown on the upper right (shaded in magenta).

DOI: http://dx.doi.org/10.7554/eLife.25885.002