Abstract
Methylobacterium extorquens AM1 was used to explore the genetics of dephosphotetrahydromethanopterin (dH(4)MPT) biosynthesis. Strains with mutations in eight "archaeal-type" genes linked on the chromosome of M. extorquens AM1 were analyzed for the ability to synthesize dH(4)MPT, and six were found to be dH(4)MPT negative. Putative functions of these genes in dH(4)MPT biosynthesis are discussed.