TFIIIC mediates tRNA and 5S RNA gene activation by binding to intragenic promoter elements. Upstream of the transcription start site, TFIIIC assembles the initiation complex TFIIIB-TFIIIC-tDNA, which is sufficient for RNA polymerase III recruitment and function. Part of the tauA domain of TFIIIC that binds boxA DNA promoter sites of tRNA and similar genes. Participates in the interconnection of tauA with tauB via its contacts with TFC3 and TFC6. Serves as a scaffold critical for tauA-DNA spatial configuration and tauB-DNA stability. Component of the TFIIIC complex composed of TFC1, TFC3, TFC4, TFC6, TFC7 and TFC8. The subunits are organized in two globular domains, tauA and tauB, connected by a proteolysis-sensitive and flexible linker. Interacts with TFC3, TFC4 and TFC6. Present with 15800 molecules/cell in log phase SD medium. Belongs to the TFIIIC subunit 5 family.