Part of the twin-arginine translocation (Tat) system that transports large folded proteins containing a characteristic twin-arginine motif in their signal peptide across membranes. Forms a complex with TatA. H.volcanii possesses two TatC translocases: TatCo and TatCt. Both paralogs are structurally atypical and may represent adaptation to the extensive utilization of the Tat pathway in haloarchaea (PubMed:16291683). Belongs to the TatC family.