A Second Nitrogenase-like Enzyme for Bacteriochlorophyll Biosynthesis
In most photosynthetic organisms, the chlorin ring structure of chlorophyll a is formed by the reduction of the porphyrin D-ring by the dark-operative nitrogenase-like enzyme, protochlorophyllide reductase (DPOR). Subsequently, the chlorin B-ring is reduced in bacteriochlorophyll biosynthesis to form a bacteriochlorin ring structure. Phenotypic analysis of mutants lacking one of three genes, bchX, bchY, or bchZ, which show significant sequence similarity to the structural genes of nitrogenase, suggests that a second nitrogenase-like enzyme is involved in the chlorin B-ring reduction.
26 May 2006 ... RECONSTITUTION OF CHLOROPHYLLIDE a REDUCTASE WITH PURIFIED X- PROTEIN (BchX) AND YZ-PROTEIN (BchY-BchZ) FROM ...