Arabidopsis calcium-binding mitochondrial carrier proteins as potential facilitators of mitochondrial ATP-import and plastid SAM-import

► First characterization of EF-hand containing Ca2+-binding MCF proteins. ► Phylogeny indicates two functionally unrelated sub-families. ► Unknown carrier of the SAMTL family at chloroplasts as potential SAM transporter. ► Three carriers at mitochondria are likely Ca2+-regulated ATP-Mg/Pi transporters.