Extended Data Fig. 5: Relationship between P6C and vitamin B6 biosynthesis pathway in plants.

Vitamin B6 vitamers comprise of PN (pyridoxine), PL (pyridoxal) and PM (pyridoxamine) and their phosphorylated forms PNP, PLP and PMP, respectively. PL and PLP form multiple complexes with P6C. De novo synthesis of PLP involves ribose 5-phosphate (R5P), glyceraldehyde-3-phosphate (Gl3P) and glutamine and is catalysed by PDX1 and PDX2 enzymes. Conversion of PN, PL and PM to their phosphorylated forms is mediated by SOS4. Pase indicates the phosphatase that converts PMP, PLP, and PNP to their non-phosphorylated forms. PDX3 is an oxidase that converts PMP and PNP to PLP. Tase refers to transaminase.