The invention relates to a nucleic acid that encodes a plant transporter of the inner mitochondrial membrane, in particular a member of the mitochondrial carrier family (MCF), and uses of this nucleic acid. The invention furthermore relates to a fragment of the nucleic acid, a construct containing the nucleic acid or a fragment thereof, and a host cell that contains the nucleic acid, the fragment, or the construct. The present invention furthermore relates to a method for producing a transgenic plant by using the nucleic acid, a fragment thereof, or a construct containing the nucleic acid or a fragment thereof, as well as a method for modulating the transport properties of the inner mitochondrial membrane of a plant, a plant part, a plant cell and/or seeds.