Distribution and functional analysis of the two types of 8-vinyl reductase involved in chlorophyll biosynthesis in marine cyanobacteria

In the chlorophyll biosynthesis pathway, 8-vinyl group of precursor is reduced to an ethyl by reductase. Two isozymes reductase have been described in oxygenic photosynthetic organisms: one encoded BciA and another BciB. Only BciB contains [Fe-S] cluster most cyanobacteria harbor this form; whereas a few contain BciA. Given disparity distribution, cyanobacterial has remained largely overlooked, which limited understanding these microorganisms. Here, we reveal that encodes functional reductase, as evidenced measuring vitro activity recombinant Synechococcus Acaryochloris Genomic comparison revealed had replaced during evolution marine cyanobacterium Synechococcus, coincided with replacement Fe-superoxide dismutase (SOD) Ni-SOD. These findings imply acquisition confers adaptive advantage living low-iron oceanic environments.