Component of RNA polymerase I (Pol I), a DNA-dependent RNA polymerase which synthesizes ribosomal RNA precursors using the four ribonucleoside triphosphates as substrates (PubMed:24207024, PubMed:34671025, PubMed:34887565, PubMed:36271492). Appears to be involved in the formation of the initiation complex at the promoter by mediating the interaction between Pol I and UBTF/UBF (PubMed:24207024). {ECO:0000269|PubMed:24207024, ECO:0000269|PubMed:34671025, ECO:0000269|PubMed:34887565, ECO:0000269|PubMed:36271492}. This is the function of ENSG00000137054 (POLR1E, RNA polymerase I subunit E).