Open AccessMitochondrial 16S rRNA Is Methylated by tRNA Methyltransferase TRMT61B in All Vertebrates
Author(s) -
Dan Bar-Yaacov,
Idan Frumkin,
Yuka Yashiro,
Takeshi Chujo,
Yuma Ishigami,
Yonatan Chemla,
Amit Blumberg,
Orr Schlesinger,
Philipp Bieri,
B.J. Greber,
Nenad Ban,
Raz Zarivach,
Lital Alfonta,
Yitzhak Pilpel,
Tsutomu Suzuki,
Dan Mo
Publication year - 2016
Publication title -
plos biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.127
H-Index - 271
eISSN - 1545-7885
pISSN - 1544-9173
DOI - 10.1371/journal.pbio.1002557
Subject(s) - biology , mitochondrial ribosome , transfer rna , ribosome , mitochondrial dna , ribosomal rna , 23s ribosomal rna , genetics , methyltransferase , dna , rna , biochemistry , methylation , gene
The mitochondrial ribosome, which translates all mitochondrial DNA (mtDNA)-encoded proteins, should be tightly regulated pre- and post-transcriptionally. Recently, we found RNA-DNA differences (RDDs) at human mitochondrial 16S (large) rRNA position 947 that were indicative of post-transcriptional modification. Here, we show that these 16S rRNA RDDs result from a 1-methyladenosine (m 1 A) modification introduced by TRMT61B, thus being the first vertebrate methyltransferase that modifies both tRNA and rRNAs. m 1 A947 is conserved in humans and all vertebrates having adenine at the corresponding mtDNA position (90% of vertebrates). However, this mtDNA base is a thymine in 10% of the vertebrates and a guanine in the 23S rRNA of 95% of bacteria, suggesting alternative evolutionary solutions. m 1 A, uridine, or guanine may stabilize the local structure of mitochondrial and bacterial ribosomes. Experimental assessment of genome-edited Escherichia coli showed that unmodified adenine caused impaired protein synthesis and growth. Our findings revealed a conserved mechanism of rRNA modification that has been selected instead of DNA mutations to enable proper mitochondrial ribosome function.