24 ホスホマイシンの生合成研究(口頭発表の部)

抄録

Fosfomycin is a clinically used antibiotic possessing a unique C-P bond and an epoxide. Through the biosynthetic studies on fosfomycin using Streptomyces wedmorensis, we revealed that its biosynthetic pathway consisted of 4 steps: (1) intramolecular rearrangement of phosphoenolpyruvate to phosphonopyruvic acid (PnPy) catalyzed by phosphoenolpyruvate phosphomutase, (2) decarboxylation of PnPy to generate phosphonoacetaldehyde (PnAA), (3) methylation of PnAA to provide 2-hydroxypropylphosphonic acid (HPP), and (4) epoxide formation to form the final product. It should be emphasized that the epoxide is formed by dehydrogenation of the alcohol function of HPP and that unlike usual epoxidation, the molecular oxygen is not incorporated into fosfomycin. In addition, we have cloned the genes responsible for the biosynthesis of fosfomycin which were clustered in an about 11.0kb fragment on the chromosome. The nucleotide sequence of the fragment revealed the presence of 10 open reading frames including four biosynthetic genes and two resistance genes.