Figure 1

Genome-wide mapping of dTFIIIC220 in D. melanogaster . (a) Example ChIP-seq profile shown for dTFIIIC220 (red) over a tRNA cluster on Drosophila chromosome 2R, co-bound by TFIIIB subunits TRF1 and BRF. (b,c) Tag density enrichment profiles for dTFIIIC220 over all annotated tDNAs (B) and over sites previously identified as bound by TFIIIB complex subunits TRF1 and BRF (C) confirms the expected genome-wide localization patterns for Drosophila (overlap significance P < 0.00001, permutation test). RPM, reads per million. (d) Consensus sequences identified de novo by MEME-ChIP reveals evolutionarily conserved Drosophila B box and A box elements present in dTFIIIC220-bound tRNA genes. (e) Central motif enrichment (CentriMo) plot for B box and A box sequences with respect to dTFIIIC220 ChIP-seq peaks at tRNA genes. (f) Overlap between dTFIIIC220 peaks, independently identified in two biological replicates at a false discovery rate of 5%, with annotated tRNA genes obtained from Flybase (P < 0.00001, permutation test). Non-overlapping sites indicate thousands of ETC loci in D. melanogaster, of which 348 contain the B box binding motif (14.5%, P < 0.00001, permutation test).