Fig 1: Study workflow and combinatorial atlas of human RNA Polymerase III subunits across canonical Pol III-transcribed genes.a Illustration of experimental approach tracing the effect of developmental loss of subunit POLR3G, subunit-specific disruption of POLR3G, and cancer-associated re-establishment of POLR3G and accompanying chromatin features, which collectively identify POLR3G-driven modulation of Pol III transcription potential in proliferating cells. b Pol III subunit and transcription factor legend corresponding to genome-wide maps in panels c–k, including POLR3A/RPC1 (3A); POLR3B/RPC2 (3B); POLR1D/RPAC2 (1D); POLR3C/RPC3 (3C); POLR3G/RPC7a (3G); POLR3GL/RPC7ß (3GL); POLR3D/RPC4 (3D); POLR3E/RPC5 (3E); BRF1/TFIIIB90; TF3C1/TFIIIC220. Corresponding subcomplex indicated. c–k Example ChIP-seq read signals for each subunit/factor are shown in THP-1 monocytes across canonical Pol III-transcribed genes of varying promoter architecture, including ribosomal 5 S rRNA genes (type 1 promoter; panel c), tRNA, 7SL, vault, and snaR-A ncRNA genes (type 2 promoter, panels d–g, respectively), and Y, U6, 7SK, and RMRP ncRNA genes (type 3 promoter, panels h–k, respectively). Gene labels include Unique RNA Sequence (URS) identifiers assigned by (and connected to) the RNAcentral database. Bottom panel illustrates corresponding promoter architecture classification. l Cartoon schematic of the Pol III protein complex with emphasis on subunits mapped in this study (labeled) and the corresponding color code for genomic signal plots. Illustration serves as general reference guide inspired by previous structural reconstructions (Hoffmann et al., Nature 2015)46. m Visualization of the correlation between log2(normalized read densities) for paralogous Pol III subunits, POLR3G and POLR3GL, at Pol III complex–occupied genes in THP-1 monocytes. Source Data are provided as a Source Data file.