Two functional sites of phosphatidylglycerol for regulation of reaction of plastoquinone QB in photosystem II

► Phosphatidylglycerol was depleted from cyanobacterial pgsA-gene-inactivated cells. ► Two PG molecules regulate activities of QB and oxygen evolution differently. ► Loss of high-affinity PGH inhibits QB directly and suppress intrinsic O2 evolution. ► Loss of low-affinity PGL enhances PSII affinity to BQ that inactivates QB. ► Binding sites of PGH and PGL in PS II structure are estimated.