As part of the MCIA complex, primarily participates in the assembly of the mitochondrial complex I and therefore plays a role in oxidative phosphorylation (PubMed:20816094, PubMed:24158852, PubMed:32320651). This moonlighting protein has also a dehydrogenase activity toward a broad range of substrates with greater specificity for long-chain unsaturated acyl-CoAs (PubMed:12359260, PubMed:16020546, PubMed:21237683, PubMed:24158852). However, in vivo, it does not seem to play a primary role in fatty acid oxidation (PubMed:20816094, PubMed:24158852). In addition, the function in complex I assembly is independent of the dehydrogenase activity of the protein (PubMed:24158852).
