Figure 1

The Metabolically Coupled Replicator System with folded RNA molecules. A: The MCRS concept: M represents the hypothetical metabolic reaction network (metabolism). All reactions of M are catalysed by different replicators with enzymatic activities {1} (blue arrow), {2} (red arrow) and {3} (green arrow). The metabolism produces monomers (yellow arrows) which are the common resource of all replicator types (solid arrows). Each replicator is folded into 2D structures (dashed arrows) which may acquire catalytically active (coloured) regions including “active” and “helper” (boldface) bases. A parasitic sequence not contributing to monomer production (no arrow to M) but consuming monomers, is shown in white (no enzymatically active region). B: Colours represent catalitically active regions within a sequence; α is the catalytic efficiency of the given region (detailed explanation in text).