Roles of DevBCA-like ABC transporters in the physiology of Anabaena sp. PCC 7120.

The filamentous, photosynthetic cyanobacterium Anabaena sp. PCC 7120 can be considered as a true multicellular bacterium. Along the filament of cells, nitrogen fixation is spatially separated from the incompatible process of oxygenic photosynthesis by the formation of specialized heterocysts in a semiregular pattern. Heterocyst development involves many proteins, including a group of DevBCA-HgdD-like tripartite efflux pumps driven by ATP-binding cassette (ABC) transporters and that share similarity with MacAB or LolCDE transporters. In this minireview, we summarize the results from our studies of this group of transporters in Anabaena sp. PCC 7120 and discuss what remains to be elucidated.