NU4LM_HYPJE 89 Core subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase (Complex I) that is believed to belong to the minimal assembly required for catalysis. Complex I functions in the transfer of electrons from NADH to the respiratory chain. The immediate electron acceptor for the enzyme is believed to be ubiquinone (By similarity). NADH dehydrogenase subunit 4L NADH-ubiquinone oxidoreductase chain 4L ND4L NAD4L MSLTLVLFLIGILGFVFNRKNIILMLISIEIMLLSITFLILVSSINLDDIIGQTYAIYIIVVAGAESAIGLAILVAFYRLRGSIAIEYK