Fig 1. Construction of the coaR-PcoaT::furA fusion strain AGcoaRFurA.
(A) The normal promoter region of the furA gene in the Anabaena sp. PCC 7120 chromosome was replaced with the divergent cobalt/zinc-inducible coaT promoter (PcoaT) and the coding region of the transcriptional activator CoaR from Synechocystis sp. PCC 6803. (B) Levels of FurA protein in wild-type Anabaena sp. strain PCC 7120, the furA-overexpressing strain AG2770FurA and the coaR-PcoaT::furA fusion strain AGcoaRFurA, revealed by Western blotting. Total cell extracts from filaments grown in Co2+/Zn2+ deprived medium (BG-11-Co/Zn) were separated in duplicate by SDS-PAGE, electrotransferred, and challenged with anti-FurA antiserum. Molecular weight is indicated. (C) furA expression in mid-log phase cultures of wild-type and AGcoaRFurA strains growing with and without Co2+/Zn2+, according to sqRT-PCR. Expression of the housekeeping gene rnpB is also shown.