Fig. 5.

Construction and detection of the ΔpsbO site-directed mutants. A, Schematic shows the construction of ΔpsbO site-directed mutant strains by homologous recombination. The kanamycin resistance (K_m^r) cassette was inserted into the SmaI restriction sites in psbO gene and the chloramphenicol resistance (Cm^r) cassette was inserted into the modified SmaI restriction sites in SYNPCC7002_A1479 gene, added to the appropriate ends of the flanking sequences (see Experimental Procedures). B, C, Agarose gel electrophoresis demonstrates complete segregation of alleles of P_cpcBA-A0269::Cm^r using A0269kn-F/R and A1479kn-F/R primers. D, Western blotting analyses of total cellular extracts from Synechococcus wild type and ΔpsbO site-directed mutants were performed using antibodies specific to PsbO and PsaC. PsbO, photosystem II manganese-stabilizing protein; ΔpsbO, PsbO knockout mutant; PsaC, photosystem I subunit VII; P_cpcBA, cpcBA promoter derived from Synechocystis.