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

Abstract

[Keywords: Saccharomyces cerevisiae; guanylyltransferase; tRNA processing; YGR024c] Supplemental material is available at http://www.genesdev.org.

The 2′-O-methyltransferase responsible for modification of yeast tRNA at position 4

“…reading frame (MORF) library of yeast strains, each of which expresses a yeast ORF fused at its C terminus to a tri-partite affinity tag (Gelperin et al 2005). To do this, we used the biochemical genomics approach described previously for another genomic library (Xing et al 2002;Gu et al 2003;Jackman et al 2003;Alexandrov et al 2005), employing pools of purified proteins. We first assayed pools of purified ORF-fusion proteins, each derived from 96 strains expressing ORFs, and found that pool 45 has the appropriate 29-O-methyltransferase activity (Fig.…”

“…However, since ligation of the 3-nucleotide (nt) 59 fragment from tRNA His does not readily occur, the labeled 39-half-molecule was ligated to a synthetic 18-mer RNA comprised of a 15-residue leader and the first 3 nt of tRNA . This 59-extended tRNA His molecule was cleaved in a second RNase H reaction (Gu et al 2003) designed to produce a full-length, specifically labeled, wild-type tRNA His (C 3 *His), which was subsequently purified by PAGE.…”

Large gene overlaps and tRNA processing in the compact mitochondrial genome of the crustaceanArmadillidium vulgare

“…30 Finally, the G -1 is incorporated thanks to a tRNA His -dependent guanylyl transferase. Indeed, ESTs encoding a mt homolog of Thg1p, the cytosolic S. cerevisiae tRNA His -dependent guanylyl transferase, 32 were retrieved from A. vulgare EST libraries (Fig. S3).…”

Have tRNA, will travel

“…Understanding the biochemistry of tRNA processing has led to its share of surprises, including the discovery of RNA catalysis by RNase P (30), of a new metabolite of nicotinamide adenine dinucleotide (NAD) formed during tRNA splicing (31), of multiple ligation pathways of tRNA splicing (32), of tRNA splicing enzymes that splice mRNA (33), of the only known polymerase that is templateindependent and sequence-specific (34), and of an enzyme that can add a nucleotide to a polynucleotide chain to extend it in the reverse (3Ј35Ј) direction (35). Clearly the location of tRNA processing events has had as big an impact as the biochemical steps themselves on the biology of tRNA.…”