The yfiC gene of E. coli encodes an adenine-N6 methyltransferase that specifically modifies A37 of tRNA1Val(cmo5UAC)

Anna Y. Golovina; Petr V. Sergiev; Andrey V. Golovin; Marina V. Serebryakova; Irina Demina; Vadim M. Govorun; Olga A. Dontsova

doi:10.1261/rna.1494409

The yfiC gene of E. coli encodes an adenine-N6 methyltransferase that specifically modifies A37 of tRNA₁^Val(cmo⁵UAC)

¹Department of Chemistry, Moscow State University, Moscow, 119992, Russia
²A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119992, Russia
³Research Institute for Physical-Chemical Medicine, Ministry of Public Health of Russian Federation, 119992 Malaya Pirogovskaya 1a, Moscow, Russia

Abstract

Transfer RNA is highly modified. Nucleotide 37 of the anticodon loop is represented by various modified nucleotides. In Escherichia coli, the valine-specific tRNA (cmo⁵UAC) contains a unique modification, N⁶-methyladenosine, at position 37; however, the enzyme responsible for this modification is unknown. Here we demonstrate that the yfiC gene of E. coli encodes an enzyme responsible for the methylation of A37 in tRNA₁^Val. Inactivation of yfiC gene abolishes m⁶A formation in tRNA₁^Val, while expression of the yfiC gene from a plasmid restores the modification. Additionally, unmodified tRNA₁^Val can be methylated by recombinant YfiC protein in vitro. Although the methylation of m⁶A in tRNA₁^Val by YfiC has little influence on the cell growth under standard conditions, the yfiC gene confers a growth advantage under conditions of osmotic and oxidative stress.

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Footnotes

Reprint requests to: Petr V. Sergiev, Department of Chemistry, Moscow State University, Moscow, 119992, Russia, and A.N. Belozersky Institute of Physico-Chemical Biology, Laboratory Building A, Moscow State University, Moscow, 119992, Russia; e-mail: petya{at}genebee.msu.su; fax: 7-495-9393181.
Article published online ahead of print. Article and publication date are at http://www.rnajournal.org/cgi/doi/10.1261/rna.1494409.
- Received December 2, 2008.
- Accepted February 27, 2009.