RNA with iron(II) as a cofactor catalyses electron transfer
Journal
Nature Chemistry
Journal Volume
5
Journal Issue
6
Pages
525 - 528
Date Issued
2013
Author(s)
Chou, I-Chun
Okafor, C. Denise
Bowman, Jessica C.
O'neill, Eric B.
Athavale, Shreyas S.
Petrov, Anton S.
Hud, Nicholas V.
Wartell, Roger M.
Harvey, Stephen C.
Williams, Loren Dean
Abstract
Mg(2+) is essential for RNA folding and catalysis. However, for the first 1.5 billion years of life on Earth RNA inhabited an anoxic Earth with abundant and benign Fe(2+). We hypothesize that Fe(2+) was an RNA cofactor when iron was abundant, and was substantially replaced by Mg(2+) during a period known as the 'great oxidation', brought on by photosynthesis. Here, we demonstrate that reversing this putative metal substitution in an anoxic environment, by removing Mg(2+) and replacing it with Fe(2+), expands the catalytic repertoire of RNA. Fe(2+) can confer on some RNAs a previously uncharacterized ability to catalyse single-electron transfer. We propose that RNA function, in analogy with protein function, can be understood fully only in the context of association with a range of possible metals. The catalysis of electron transfer, requisite for metabolic activity, may have been attenuated in RNA by photosynthesis and the rise of O2.
Type
journal article