Required for the preservation of the structural and functional integrity of mitochondrial respiratory complex III by allowing the physiological turnover of the Rieske protein UQCRFS1 (PubMed:21278747, PubMed:28673544). Involved in the clearance of UQCRFS1 N-terminal fragments, which are produced upon incorporation of UQCRFS1 into the complex III and whose presence is detrimental for its catalytic activity (PubMed:28673544). Binds to the mature mitochondrial complex III dimer, after the incorporation of the Rieske protein UQCRFS1 (PubMed:28673544). Interacts with UQCRC1 and UQCRFS1 (By similarity). Interacts with ZFYVE26 and CHMP4B (PubMed:20208530). The disease is caused by variants affecting the gene represented in this entry. Belongs to the TTC19 family. Was reported to be required for the abcission step in cytokinesis, possibly regulating the ESCRT-III complex via its interaction with CHMP4B (PubMed:20208530). According to the same authors, localizes to the centrosome during all stages of the cell cycle and is recruited to the midbody during cytokinesis (PubMed:20208530). However, the midbody localization could not be confirmed by others (PubMed:21278747). Extended N-terminus. Extended N-terminus. Extended N-terminus. Extended N-terminus. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus. Extended N-terminus.