NDUFB5 (NADH: Ubiquinone Oxidoreductase Subunit B5) is a Protein Coding gene. Among its related pathways are Metabolism and Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins. The protein encoded by NDUFB5 is a subunit of the multisubunit NADH: ubiquinone oxidoreductase (complex I). Mammalian complex I is composed of 45 different subunits. It locates at the mitochondrial inner membrane. This protein has NADH dehydrogenase activity and oxidoreductase activity.