An improved system for the targeted mutagenesis of thepsbA2gene inSynechocystissp. PCC 6803: mutation of D1-Glu244 to His impairs electron transfer between Q_Aand Q_Bof Photosystem II

Chlorophyll f synthesis by a super-rogue photosystem II complex

“…The following strains of Synechocystis sp. PCC 6803 (hereafter Syn6803) were used in this work: the glucose-tolerant wild-type strain GT-P (hereafter denoted WT) 22 ; psbA triple-deletion strains (PsbA) 23 and 4E-3H6 (hereafter His-CP47/D1) 24 ; the D1 and CP43 deletion strain, D1/CP43; the D1 and CP47 deletion strain, D1/CP47; the PSII-less strain, D1/D2/CP43/CP43, denoted here PSII -. To create the D1/CP43 strain, the psbD1C operon was removed from the D1 strain 23 by replacing the open reading frame of psbD1 (encoding D2) and psbC (encoding CP43) with a kan R -SacB selection cassette 26 .…”

“…Negative selection was performed by supplementing the BG11 medium with 5% (w/v) sucrose in the absence of kanamycin. The D1/CP47 deletion strain was also derived from the D1 deletion strain 23 by replacing the psbB gene (encoding CP47) with a gentamycin-resistance cassette. The PSII-less strain was derived from the D1/CP43 deletion strain by sequential deletion of psbB as described above and then psbD2, encoding D2, by an erythromycin-resistance cassette using standard transformation protocols 27…”

The D1:Ser268 residue of Photosystem II contributes to an alternative pathway for QB protonation in the absence of bound bicarbonate

“…PCC 6803 (hereafter referred to as Synechocystis 6803) [16,17]. The control and S268A and S268T strains were generated as described in Forsman et al [18]. All strains were grown on BG-11 media agar plates containing 5 mM glucose, 20 μM atrazine, 10 mM TES-NaOH (pH 8.2), and 0.3% sodium thiosulfate.…”

Biology and biotechnological applications of microalgae and photosynthetic prokaryotes: Part 1

“…PCC 6803, the PsbA protein is encoded by a gene family consisting of three psbA genes. The contribution by Forsman et al (2019) reports the construction of a strain that allows the introduction of targeted mutations in psbA2, the most highly expressed copy of psbA, while removing the other copies by markerless gene deletions. Synechocystis sp.…”

“…PCC 6803 is a widely used model organism; however, phenotypic variation occurs between different wild-type substrains and it is therefore important to know the genomic background of the wild type in use (Morris et al 2014(Morris et al , 2017). The mutagenesis system described in Forsman et al (2019) was constructed in the GTO1 wild-type strain derived from the glucose tolerant wild type isolated by Williams (1988).…”