A novel expression vector for the cyanobacterium, Synechococcus PCC 6301.

A cyanobacterial expression vector was constructed using ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) promoter and terminator sequences derived from Synechococcus PCC 6301. recombinant plasmid, designated pARUB19, has an ampicillin-resistant (ApR) gene as a selectable marker and four unique restriction sites to allow the insertion of foreign genes. Using this vector, the luciferase gene from the firefly, Photinus pyralis, was introduced into Synechococcus PCC 6301 cells. The luciferase expression vector could be maintained stably in the host cells. Light production of luciferin/luciferase was detected in the transformants. Luciferase amounted to 1.2% of the total soluble protein. This plasmid may facilitate higher levels of foreign gene expression in Synechococcus PCC 6301.