Fig. 1

Co-transcriptional 5ʹend processing of snoRNA. a 5ʹprocessing pathways for independently transcribed snoRNA in S. cerevisiae. b Mature independently transcribed snoRNA (including snoRNA located at the 5ʹends of polycistronic TUs) possessing or lacking caps. c-eChIP-seq analyses of Cbp20 and Rnt1 co-transcriptional recruitment to c snoRNA transcribed as 5ʹextended precursors, d polycistronic snoRNA, e snoRNA transcribed without 5ʹextension. NNS-binding sites (NBS) are shown below the reads. f ChIP analysis showing RNA-dependent recruitment (RNase sensitive) of Cbp20 and Rnt1 to RD box C/D SNR47. Average of three independent experiments is shown. Error bars represent standard deviation. g NET-seq signals originating from Rnt1 cleavage sites (RCS) in the pre-snoRNA 5ʹextensions. Note that NET-seq signals were bioinformatically depleted over sequences coding mature snoRNA. h The total number of snoRNA (including proximal snoRNA from each polycistron) displaying NET-seq signal within the RCS in the 5ʹextension. i Metagene analysis of NET-seq peaks around the AGNN loop in the snoRNA 5ʹextension; RCS –Rnt1 cleavage site, the predicted cleavage site is denoted by red vertical dotted line. Green rectangle denotes mature snoRNA while bold green line shows 5ʹextension. RCS is marked by red vertical arrow