Heatmap of AFs in 90S preribosome. 90S preribosomes assembled on WT or mutant pre-18S RNAs were affinity purified via the MS2-tag in RNA and the TAP-tag in a bait protein Utp9, Noc4, Rrp5, or Efg1. These samples are ordered roughly by their assembly degree. The samples in lanes 7, 12, and 13 were previously reported and included for comparison (Zhang et al. 2016). The sample in lane 7 (18S-1634) was derived from a pre-18S fragment ending at position 1634 of 18S. The sample in lane 12 was purified via MS2-tag and Noc4-TAP and stands for a mature and unprocessed 90S particle with most liable factors released. The sample in lane 13 was chromosome-derived 90S purified via Noc4-TAP. The relative abundance of each protein is color-coded by normalized RSAF value. Sample 1 is normalized to Efg1, samples 2 and 3 to Krr1, and the other samples to UTPB proteins. Proteins in magenta are the labile factors that are weakly associated to the mature 90S.
