Mitochondrial glycine transporter that imports glycine into the mitochondrial matrix. Plays an important role in providing glycine for the first enzymatic step in heme biosynthesis, the condensation of glycine with succinyl-CoA to produce 5-aminolevulinate (ALA) in the mitochondrial matrix. glycine(in) = glycine(out) Yeasts grow well on the fermentable carbon source dextrose, but only poorly aerobically on glycerol, indicating a defect in respiration. Furthermore, the deletion strain is unable to reduce sodium nitroprusside, indicating that the defect is likely in heme biosynthesis. Nitroprusside reduction can be rescued by supplementation of the medium with either glycine or 5-aminolevulinate (ALA) (PubMed:19412178). In combination with a disruption of MCX1, abrogates mitochondrial respiration (PubMed:25957689). Present with 1550 molecules/cell in log phase SD medium. Belongs to the mitochondrial carrier (TC 2.A.29) family. SLC25A38 subfamily.