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RNA folding and catalysis mediated by iron (II).
- Source :
-
PloS one [PLoS One] 2012; Vol. 7 (5), pp. e38024. Date of Electronic Publication: 2012 May 31. - Publication Year :
- 2012
-
Abstract
- 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.
Details
- Language :
- English
- ISSN :
- 1932-6203
- Volume :
- 7
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- PloS one
- Publication Type :
- Academic Journal
- Accession number :
- 22701543
- Full Text :
- https://doi.org/10.1371/journal.pone.0038024