Component of the type III secretion system (T3SS), also called injectisome, which is used to inject bacterial effector proteins into eukaryotic host cells (PubMed:9427408, PubMed:15231798, PubMed:24207124). Forms a ring-shaped multimeric structure with an apparent central pore in the outer membrane (PubMed:9427408, PubMed:15231798, PubMed:24207124). It may serve as an injectisome assembly platform (PubMed:24207124). Essential for the export of Yop proteins (PubMed:9427408). The core secretion machinery of the T3SS is composed of approximately 20 different proteins, including cytoplasmic components, a base, an export apparatus and a needle (PubMed:30107569). This subunit is part of the base, which anchors the injectisome in the bacterial cell envelope (PubMed:15231798, PubMed:24207124). Forms a stable homooligomeric complex (PubMed:9427408, PubMed:15231798, PubMed:24207124). The complex is composed of 12 subunits (PubMed:24207124). Interacts with the pilotin YscW/SctG, which is important for localization and efficient oligomerization of SctC (PubMed:15292137). Interacts with the inner membrane ring inner protein YscD/SctD (PubMed:24207124). Localization to the outer membrane requires YscW/SctG. The SctC complex is found in cells grown at 37 degrees Celsius, but not in cells grown at 23 degrees Celsius. Detectable in cells grown in the presence of Ca(2+), although less abundantly than in cells grown under Ca(2+) depletion. The oligomeric secretin consists of an outer membrane ring connected via a thin cylindrical wall to a conical, periplasmic region that exposes N-terminal petals connected by flexible linkers. These petals harbor the binding site of YscD/SctD, a component of the inner membrane ring. Mutant does not secrete Yop proteins. The secretion channel formed by SctC remains closed in the absence of the other components of the T3SS. Belongs to the bacterial secretin family. T3SS SctC subfamily.