|Title||RNA folding and catalysis mediated by iron (II).|
|Publication Type||Journal Article|
|Year of Publication||2012|
|Authors||Athavale, SS, Petrov, AS, Hsiao, C, Watkins, D, Prickett, CD, J Gossett, J, Lie, L, Bowman, JC, O'Neill, E, Bernier, CR, Hud, NV, Wartell, RM, Harvey, SC, Williams, LDean|
|Keywords||Catalysis, Iron, Magnesium, Nucleic Acid Conformation, RNA, RNA Folding, RNA, Catalytic, Tetrahymena thermophila|
Mg²⁺ shares a distinctive relationship with RNA, playing important and specific roles in the folding and function of essentially all large RNAs. Here we use theory and experiment to evaluate Fe²⁺ in the absence of free oxygen as a replacement for Mg²⁺ in RNA folding and catalysis. We describe both quantum mechanical calculations and experiments that suggest that the roles of Mg²⁺ in RNA folding and function can indeed be served by Fe²⁺. The results of quantum mechanical calculations show that the geometry of coordination of Fe²⁺ by RNA phosphates is similar to that of Mg²⁺. Chemical footprinting experiments suggest that the conformation of the Tetrahymena thermophila Group I intron P4-P6 domain RNA is conserved between complexes with Fe²⁺ or Mg²⁺. The catalytic activities of both the L1 ribozyme ligase, obtained previously by in vitro selection in the presence of Mg²⁺, and the hammerhead ribozyme are enhanced in the presence of Fe²⁺ compared to Mg²⁺. All chemical footprinting and ribozyme assays in the presence of Fe²⁺ were performed under anaerobic conditions. The primary motivation of this work is to understand RNA in plausible early earth conditions. Life originated during the early Archean Eon, characterized by a non-oxidative atmosphere and abundant soluble Fe²⁺. The combined biochemical and paleogeological data are consistent with a role for Fe²⁺ in an RNA World. RNA and Fe²⁺ could, in principle, support an array of RNA structures and catalytic functions more diverse than RNA with Mg²⁺ alone.
|Alternate Journal||PLoS ONE|
|PubMed Central ID||PMC3365117|