A primordial tRNA modification required for the evolution of life?

Abstract

The evolution of reading frame maintenance must have been an early event, and presumably preceded the emergence of the three domains Archaea, Bacteria and Eukarya. Features evolved early in reading frame maintenance may still exist in present-day organisms. We show that one such feature may be the modified nucleoside 1-methylguanosine (m(1)G37), which prevents frameshifting and is present adjacent to and 3' of the anticodon (position 37) in the same subset of tRNAs from all organisms, including that with the smallest sequenced genome (Mycoplasma genitalium), and organelles. We have identified the genes encoding the enzyme tRNA(m(1)G37)methyltransferase from all three domains. We also show that they are orthologues, and suggest that they originated from a primordial gene. Lack of m(1)G37 severely impairs the growth of a bacterium and a eukaryote to a similar degree. Yeast tRNA(m(1)G37)methyltransferase also synthesizes 1-methylinosine and participates in the formation of the Y-base (yW). Our results suggest that m(1)G37 existed in tRNA before the divergence of the three domains, and that a tRNA(m(1)G37)methyltrans ferase is part of the minimal set of gene products required for life.

tRNAHis maturation: An essential yeast protein catalyzes addition of a guanine nucleotide to the 5′ end of tRNAHis

“…Gcd10p/Gcd14p catalyzes formation of m 1 A 58 in a number of tRNAs (Anderson et al 1998(Anderson et al , 2000, and is essential for modification of tRNA i Met (Calvo et al 1999), and Tad2p/Tad3p catalyzes formation of I 34 in the wobble position of the anticodon of tRNA Ala (Gerber and Keller 1999), and is presumably essential for proper decoding during translation. Strains lacking each of three other modification enzymes are viable, but have distinct growth defects (Lecointe et al 1998;Bjork et al 2001;Pintard et al 2002), whereas lack of most other modification proteins has only subtle growth defects.…”

S-Adenosylmethionine Synthetase 3 Is Important for Pollen Tube Growth

“…tRNA Isolation and UPLC Analysis tRNA was prepared from total RNA as described (Björk et al, 2001) using 150 mg of pollen for each sample. tRNA was eluted with buffer (10 mM Tris-H 3 PO 4 , pH 6.3, 15% ethanol, and 600 mM KCl), and 40 mg of tRNA was recovered.…”

“…tRNA was eluted with buffer (10 mM Tris-H 3 PO 4 , pH 6.3, 15% ethanol, and 600 mM KCl), and 40 mg of tRNA was recovered. 5S RNA was not eluted from the column, as it requires at least 650 mM for elution (Björk et al, 2001). Forty micrograms of purified tRNA was digested with Nuclease P1 for 16 h at 37°C and then treated with bacterial alkaline phosphatase for 2 h at 37°C.…”

Glutaredoxin GRXS17 Associates with the Cytosolic Iron-Sulfur Cluster Assembly Pathway

“…Seedlings were frozen in liquid nitrogen, and total RNA was extracted according to Björk et al (2001). One-half microgram of total RNA was resolved on 8% acrylamide gels containing 0.53 TBE, 7 M urea, and 50 mg/mL APM.…”