Fig 4. Cytosolic threonine aldolase is the main soruce of glycine for heme synthesis.
A) Glycine can be synthesized in glucose grown yeast via three enzymes, Gly1 (threonine aldolase), and cytosolic (Shm2) and mitochondrial (Shm1) serine hydroxymethyltransferases. B) Yeast cells of the indicated genotypes were grown to mid-log phase and cells were processed for glycine and heme determination. Wild type glycine was 6.0 nmol/108 cells. C) Cells of the indicated genotypes were grown to mid-log phase and 1:10 serial dilutions plated on SD medium with no supplements.