PT  - JOURNAL ARTICLE
AU  - Melanie A. Preston
AU  - Douglas F. Porter
AU  - Fan Chen
AU  - Natascha Buter
AU  - Christopher P. Lapointe
AU  - Sunduz Keles
AU  - Judith Kimble
AU  - Marvin Wickens
TI  - Unbiased screen of RNA tailing enzymes at single-nucleotide resolution reveals a poly(UG) polymerase required for genome integrity and RNA silencing
AID  - 10.1101/422972
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 422972
4099  - http://biorxiv.org/content/early/2018/09/20/422972.short
4100  - http://biorxiv.org/content/early/2018/09/20/422972.full
AB  - Ribonucleotidyl transferases (rNTases) add non-templated ribonucleotides to diverse RNAs. We developed a screening strategy in S. cerevisiae to identify sequences added by candidate enzymes from different organisms at single-nucleotide resolution. The rNTase activities of 19 previously unexplored enzymes were determined. In addition to poly(A)- and poly(U)-adding enzymes, we identified a C-adding enzyme that is likely part of a two-enzyme system that adds CCA to tRNAs in a eukaryote; a nucleotidyl transferase that adds nucleotides to RNA without apparent nucleotide preference; and a poly(UG) polymerase, C. elegans MUT-2, which adds alternating U and G nucleotides to form poly(UG) tails. MUT-2 is known to be required for certain forms of RNA silencing, and mutations in the enzyme that are defective in silencing also fail to add poly(UG) tails in our assay. We propose that MUT-2 poly(UG) polymerase activity is required to promote genome integrity and RNA silencing.