The PsbZ subunit of Photosystem II in Synechocystis sp. PCC 6803 modulates electron flow through the photosynthetic electron transfer chain |
| |
| Authors: | Cleo L Bishop Simin Ulas Elena Baena-Gonzalez Eva-Mari Aro Saul Purton Jonathan H A Nugent Pirkko Mäenpää |
| |
| Institution: | (1) Photosynthesis Research Group, Department of Biology, University College London, Darwin Building, Gower Street, London, WC1E 6BT, UK;(2) Department of Biology, Turku University, Turku, 20 014, Finland;(3) Present address: Institute of Cellular and Molecular Sciences, Bart’s and the London Queen Mary’s School of Medicine and Dentistry, 4 Newark Street, London, E1 2AT, UK;(4) Present address: Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA |
| |
| Abstract: | The psbZ gene of Synechocystis sp. PCC 6803 encodes the ∼6.6 kDa photosystem II (PSII) subunit. We here report biophysical, biochemical and in vivo characterization
of Synechocystis sp. PCC 6803 mutants lacking psbZ. We show that these mutants are able to perform wild-type levels of light-harvesting, energy transfer, PSII oxygen evolution,
state transitions and non-photochemical quenching (NPQ) under standard growth conditions. The mutants grow photoautotrophically;
however, their growth rate is clearly retarded under low-light conditions and they are not capable of photomixotrophic growth.
Further differences exist in the electron transfer properties between the mutants and wild type. In the absence of PsbZ, electron
flow potentially increased through photosystem I (PSI) without a change in the maximum electron transfer capacity of PSII.
Further, rereduction of P700+ is much faster, suggesting faster cyclic electron flow around PSI. This implies a role for PsbZ in the regulation of electron
transfer, with implication for photoprotection. |
| |
| Keywords: | Non-photochemical quenching Photosynthesis Photosystem II PsbZ Synechocystis sp PCC 6803 |
| 本文献已被 PubMed SpringerLink 等数据库收录！ |
|
