Molecular crowding facilitates ribozyme-catalyzed RNA assembly

Abstract

Catalytic RNAs or ribozymes are considered to be central to primordial biology. Most ribozymes require moderate to high concentrations of divalent cations such as Mg2+ to fold into their catalytically competent structures and perform catalysis. However, undesirable effects of Mg2+ such as hydrolysis of reactive RNA building blocks and degradation of RNA structures are likely to undermine its beneficial roles in ribozyme catalysis. Further, prebiotic cell-like compartments bounded by fatty acid membranes are destabilized in the presence of Mg2+, making ribozyme function inside prebiotically relevant protocells a significant challenge. Therefore, we sought to identify conditions that would enable ribozymes to retain activity in low concentrations of Mg2+. Inspired by the ability of ribozymes to function inside crowded cellular environments with View larger version (19K): org.highwire.dtl.DTLVardef@17d282borg.highwire.dtl.DTLVardef@1d8531aorg.highwire.dtl.DTLVardef@1380f7borg.highwire.dtl.DTLVardef@180708f_HPS_FORMAT_FIGEXP M_FIG C_FIG SYNOPSISMolecular crowding enables ribozyme-catalyzed RNA assembly under low Mg2+ conditions, and consequently may have played an essential role in the origin and evolution of RNA-based primordial life.