Disease relevance of tRNA-His

• The 'in vivo' decoding properties of four tRNAHis isoacceptors, two from Drosophila melanogaster and two from brewer's yeast, were studied after their microinjection, along with turnip yellow mosaic virus (TYMV) coat protein mRNA, into Xenopus laevis oocytes [1].
• Compared with E. coli HisRS, microhelixHis is a much poorer substrate relative to full-length tRNAHis for the yeast enzyme [2].
• Using this single-round infection system, we demonstrated that HIV-1 with a PBS complementary to tRNAIle or tRNAHis is three- to fivefold less efficient in replication as measured by production of drug-resistant cell colonies compared to the wild-type virus [3].

High impact information on tRNA-His

• Our results show that, under competing 'in vivo' conditions, the Drosophila tRNAHis with the anticodon GUG clearly prefers the histidine codon CAC to the codon CAU, whereas little preference is observed for the tRNAHis with the anticodon QUG for the codon CAU, and no preference for either codon by the two yeast isoacceptors [1].
• Queuosine modification of the wobble base in tRNAHis influences 'in vivo' decoding properties [1].
• The combination of identity elements found in tRNAHis species from archaea, eubacteria, and organelles (G-1/C73) is the most efficient for determining histidylation of the duplexes [4].
• PIVB RNA mainly contained tRNAArg (51.8%), tRNALys (17.1%), and tRNAHis (9.2%) which together accounted for 78% of the total PIVB tRNA [5].
• Previous studies of Escherichia coli histidyl-tRNA synthetase (HisRS) have demonstrated the importance of the G-1:C73 base pair to tRNAHis identity [2].

Biological context of tRNA-His

• In bacteria, archaea, and eukaryotic organelles, G-1 base pairs with C73, while in eukaryotic cytoplasmic tRNAHis, G-1 is opposite A73 [2].
• In this study, two chemically synthesized 24-nucleotide RNA microhelices, each of which recapitulates the acceptor stem of either E. coli or Saccharomyces cervisiae tRNAHis, were used to facilitate an atomic group "mutagenesis" study of the -1:73 base pair recognition by S. cerevisiae HisRS [2].
• To investigate the process of reversion, we have constructed defective proviral genomes that contain a PBS complementary to tRNAIle or tRNAHis [3].
• Previous studies have shown that HIV-1 could use alternative tRNAs, such as tRNAIle or tRNAHis, to initiate reverse transcription only if the primer binding site (PBS) was made complementary to the 3' terminal 18 nucleotides of the cognate tRNA [3].
• The highly conserved tRNAHis guanylyltransferase Thg1p interacts with the origin recognition complex and is required for the G2/M phase transition in the yeast Saccharomyces cerevisiae [6].

References