PT  - JOURNAL ARTICLE
AU  - Rebecca Guth-Metzler
AU  - Marcus S. Bray
AU  - Suttipong Suttapitugsakul
AU  - Claudia Montllor-Albalate
AU  - Jessica C. Bowman
AU  - Ronghu Wu
AU  - Amit R. Reddi
AU  - C. Denise Okafor
AU  - Jennifer B. Glass
AU  - Loren Dean Williams
TI  - Cutting in-line with iron: ribosomal function and non-oxidative RNA cleavage
AID  - 10.1101/851097
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 851097
4099  - http://biorxiv.org/content/early/2019/11/22/851097.short
4100  - http://biorxiv.org/content/early/2019/11/22/851097.full
AB  - Divalent metal cations are essential to the structure and function of the ribosome. Previous characterizations of ribosome structure and function performed under standard laboratory conditions have implicated Mg2+ as the primary mediator of ribosomal structure and function. The contribution of Fe2+ as a ribosomal cofactor has been largely overlooked, despite the ribosome’s evolution in a high Fe2+ environment, and its continued use by obligate anaerobes inhabiting high Fe2+ niches. Here we show that (i) iron readily cleaves RNA by a non-oxidative mechanism that has not been detected previously, (ii) functional ribosomes purified from cells grown under low O2, high Fe2+ conditions are associated with Fe2+, (iii) a small subset of Fe2+ that is associated with the ribosome is not exchangeable with surrounding cations, presumably because they are highly coordinated by rRNA. In total, these results expand the ancient role of iron in biochemistry, suggest a novel method for regulation of translation by iron, and highlight a possible new mechanism of iron toxicity.Key Pointsiron readily cleaves RNA by a non-oxidative mechanism that has not been detected previously;functional ribosomes purified from cells grown under low O2, high Fe2+ conditions are associated with Fe2+;a small subset Fe2+ that is associated with the ribosome is not exchangeable.