 multistep synthesis in the laboratory typically requires numerous reaction vessels , each containing a different set of reactants . in contrast , cells are capable of performing highly efficient and selective multistep biosynthesis under mild conditions with all reactants simultaneously present in solution . if the latter approach could be applied in the laboratory , it may improve the ease , speed , and efficiency of multistep reaction sequences . 
 here we show that a dna mechanical device a dna walker moving along a dna track can be used to perform a series of amine acylation reactions in a single solution without any external intervention . 
 the multistep products generated by this primitive ribosome mimetic are programmed by the sequence of the dna track , are unrelated to the structure of dna , and are formed with speeds and overall yields significantly greater than those previously achieved by multistep dna - templated small - molecule synthesis . 
Supplementary Material