Autonomous synthesis and assembly of a ribosomal subunit on a chip

Ribosome biogenesis is an efficient and complex assembly process that has not been reconstructed outside a living cell so far, yet is the most critical step for establishing a self-replicating artificial cell.
We recreated the biogenesis of Escherichia coli’s small ribosomal subunit by synthesizing and capturing all its ribosomal proteins and RNA on a chip. Surface confinement provided favorable conditions for autonomous step-wise assembly of new subunits, spatially segregated from original intact ribosomes. Our real-time fluorescence measurements revealed hierarchal assembly, cooperative interactions, unstable intermediates, and specific binding to large ribosomal subunits.
Using only synthetic genes, our methodology is a crucial step towards creation of a self-replicating artificial cell and a general strategy for the mechanistic investigation of diverse multi-component macromolecular machines.