Plasmid construction and transformation of Synechocystis 6803 with sam8. (A) sam8 was cloned into the pBluescript SK(+) plasmid. The psbA2 promoter (PpsbA2), erythromycin-resistance cassette (Erm), upstream (NS UP) and downstream (NS DW) regions of the neutral site, and the E. coli 5S t1t2 terminator were cloned into the plasmid as well. Amp: ampicillin-resistance cassette. (B) Simplified scheme of wild-type (empty vector) and sam8 transformant Synechocystis 6803. Primers used for PCR screening are indicated (arrows labeled a-d) and the expected sizes of PCR products are shown as lines beneath each map. (C) PCR screen to test for the insertion of sam8 in the mutant. WT, wild type; T, sam8 transformant. The positions of the primers are indicated in B.