Main Reaction: serine + tetrahydrofolate (THF) >> methylene-tetrahydrofolate + glycine

Reference: PubMed ID: 12646567
Authors: Patel H, Pietro ED, MacKenzie RE
Title: Mammalian fibroblasts lacking mitochondrial NAD+-dependent methylenetetrahydrofolate dehydrogenase-cyclohydrolase are glycine auxotrophs.
Published: 2003 May 23

serine + tetrahydrofolate (THF) --> methylene-tetrahydrofolate + glycine