FIG. 2.

Physical map of the pBS437V expression vector used for in vivo bilin addition to Anabaena sp. strain PCC7120 His-tagged phycoerythrocyanin apo-α subunit (HT-PecA) in E. coli. Vector pBS437V carries ht-pecA, the gene encoding HT-PecA, and the phycoerythrocyanin α subunit PCB lyase/isomerase genes pecE and pecF. Plasmid pBS437V contains the ColE1 oriV for replication in E. coli and the aadA gene conferring resistance to spectinomycin and streptomycin. Expression is controlled by the trc promoter, the lac operator, and the lacI^q gene encoding the Lac repressor. Two strong, bidirectional, ρ-independent transcriptional terminator structures from the E. coli rrnB gene are located downstream of the expression cassette. Plasmid pBS430V (see text) is equivalent to plasmid pBS437V, except that the insert contains only ht-pecA.