The emergence of protocells from a dilute prebiotic environment is a fundamental challenge in origins-of-life research which requires the simultaneous overcoming of molecular dilution, the establishment of metabolic cycles and the formation of selectively permeable compartments.
![The original role of proteins was to stabilize RNA, rather than to act as enzymes. (a) The peptidyl transferase center of the Escherichia coli ribosome [96]. The figure shows the RNA that forms the catalytic site, as identified by [97], with the three proteins that form the closest association with it: the large subunit proteins L2 (red), L4 (green) and L15 (magenta). All of these have substantial non-globular parts, which are the parts in contact with the RNA. The catalytic center is in the middle of the RNA helix. (b) The human 17S U2 snRNP involved in the first step of RNA splicing [98], showing the RNA core and the protein most closely associated with it (splicing factor 3b). Again, the part of the protein in contact with the RNA is lacking in regular secondary structure. -- LIFE via PubMed](https://astrobiology.newspackstaging.com/wp-content/uploads/2025/06/Autocatalytic-Selection-As-A-Driver.png)
