Functional Evaluation of a Nitrogenase-Like Protochlorophyllide Reductase Encoded by the Chloroplast DNA of Physcomitrella patens in

tase (DPOR) is a nitrogenase-like enzyme consisting of the two components, L-protein (a ChlL dimer) and NB-protein (a ChlN–ChlB heterotetramer), to catalyze Pchlide reduc-tion in Chl biosynthesis. While nitrogenase is distributed only among certain prokaryotes, the probable structural genes for DPOR are encoded by chloroplast DNA in lower plants. Here we show functional evaluation of DPOR encoded by chloroplast DNA in a moss Physcomitrella patens by the complementation analysis of the cyanobacter-ium Leptolyngbya boryana and the heterologous reconstitu-tion of the moss L-protein and the cyanobacterial NB-protein. Two shuttle vectors to overexpress chlL and chlN-chlB from P. patens were introduced into the cyanobac-terial chlL- and chlB-lacking mutants, respectively. Both transformants restored the ability to perform Chl biosynthe