5′‐End sequencing in Saccharomyces cerevisiae offers new insights into 5′‐ends of tRNAHis and snoRNAs. Issue 9 (4th April 2019) - Dodbele, Samantha
Abstract : tRNA H is guanylyltransferase (Thg1) specifies eukaryotic tRNA H is identity by catalysing a 3′–5′ non‐Watson–Crick (WC) addition of guanosine to the 5′‐end of tRNA H is . Thg1 family enzymes in Archaea and Bacteria, called Thg1‐like proteins (TLPs), catalyse a similar but distinct 3′–5′ addition in an exclusively WC‐dependent manner. Here, a genetic system in Saccharomyces cerevisiae was employed to further assess the biochemical differences between Thg1 and TLPs. Utilizing a novel 5′‐end sequencing pipeline, we find that a Bacillus thuringiensis TLP sustains the growth of a thg1Δ strain by maintaining a WC‐dependent addition of U−1 across from A73 . Additionally, we observe 5′‐end heterogeneity in S. cerevisiae small nucleolar RNAs (snoRNAs), an observation that may inform methods of annotation and mechanisms of snoRNA processing. Abstract :