For flawless translation of mRNA sequence into protein, tRNAs must undergo a series
of essential maturation steps to be properly recognized and aminoacylated by aminoacyl-tRNA
synthetase, and subsequently utilized by the ribosome. While all tRNAs carry a 30
-terminal CCA
sequence that includes the site of aminoacylation, the additional 50
-G-1 position is a unique feature
of most histidine tRNA species, serving as an identity element for the corresponding synthetase.
In eukaryotes including yeast, both 30
-CCA and 50
-G-1 are added post-transcriptionally by tRNA
nucleotidyltransferase and tRNAHis guanylyltransferase, respectively. Hence, it is possible that
these two cytosolic enzymes compete for the same tRNA. Here, we investigate substrate preferences
associated with CCA and G-1-addition to yeast cytosolic tRNAHis, which might result in a temporal
order to these important processing events. We show that tRNA nucleotidyltransferase accepts
tRNAHis transcripts independent of the presence of G-1; however, tRNAHis guanylyltransferase
clearly prefers a substrate carrying a CCA terminus. Although many tRNA maturation steps can
occur in a rather random order, our data demonstrate a likely pathway where CCA-addition precedes
G-1 incorporation in S. cerevisiae. Evidently, the 30
-CCA triplet and a discriminator position A73 act
as positive elements for G-1 incorporation, ensuring the fidelity of G-1 addition.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:88970 |
| Date | 11 January 2024 |
| Creators | Pöhler, Marie-Theres, Roach, Tracy M., Betat, Heike, Jackman, Jane E., Mörl, Mario |
| Publisher | MDPI |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:article, info:eu-repo/semantics/article, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 1384, 10.3390/ijms20061384 |
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