Phytyl-phosphate kinase catalyzing the conversion of phytyl-monophosphate to phytyl-diphosphate (PubMed:26452599). Involved in the activation and reutilization of phytol from chlorophyll degradation in plant metabolism, including tocopherol (vitamin E) biosynthesis (PubMed:26452599). Involved in the biosynthesis of phylloquinone (vitamin K), which is required for the photosystem I (PSI) complex stability (PubMed:28007557). a ribonucleoside 5'-triphosphate + phytyl phosphate = a ribonucleoside 5'-diphosphate + phytyl diphosphate CTP + phytyl phosphate = CDP + phytyl diphosphate Cofactor biosynthesis; tocopherol biosynthesis. A number of isoforms are produced. According to EST sequences. Lethal when homozygous. Tocopherol-deficient plants are unable to grow photoautotrophically and infertile. Vte5 and vte6 double mutants can grow photoautotrophically and display a stay-green phenotype with strongly delayed senescence and an extended lifetime. Overexpression of VTE6 results in increased phytyl-PP and tocopherol levels in seeds. Belongs to the TMEM19 family.