Dark-operative protochlorophyllide oxidoreductase generates substrate radicals by an iron-sulphur cluster in bacteriochlorophyll biosynthesis.

ABSTRACT: Photosynthesis converts solar energy to chemical energy using chlorophylls (Chls). In a late stage of biosynthesis of Chls, dark-operative protochlorophyllide (Pchlide) oxidoreductase (DPOR), a nitrogenase-like enzyme, reduces the C17 = C18 double bond of Pchlide and drastically changes the spectral properties suitable for photosynthesis forming the parental chlorin ring for Chl a. We previously proposed that the spatial arrangement of the proton donors determines the stereospecificity of the Pchlide reduction based on the recently resolved structure of the DPOR catalytic component, NB-protein. However, it was not clear how the two-electron and two-proton transfer events are coordinated in the reaction. In this study, we demonstrate that DPOR initiates a single electron transfer reaction f

SUBMITTER: Nomata J 

PROVIDER: S-EPMC4071322 | biostudies-literature | 2014 Jun

REPOSITORIES: biostudies-literature