Summerfield Tina C, Winter Regan T, Eaton-Rye Julian J
Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin, New Zealand.
Photosynth Res. 2005 Jun;84(1-3):263-8. doi: 10.1007/s11120-004-6431-3.
The sll1418 gene encodes a PsbP-like protein in Synechocystis sp. PCC 6803. Expression of sll1418 was similar in BG-11 and in Cl- - or Ca2+ -limiting media, and inactivation of sll1418 did not prevent photoautotrophic growth in normal or nutrient-limiting conditions. Also the wild-type and DeltaPsbP strains exhibited similar oxygen evolution and assembly of Photosystem II (PS II) centers. Inactivation of sll1418 in the DeltaPsbO: DeltaPsbP, DeltaPsbQ:DeltaPsbP, DeltaPsbU:DeltaPsbP and DeltaPsbV:DeltaPsbP mutants did not prevent photoautotrophy or alter PS II assembly and oxygen evolution in these strains. Moreover, the absence of PsbP did not affect the ability of alkaline pH to restore photoautotrophic growth in the DeltaPsbO:DeltaPsbU strain. The PsbO, PsbU and PsbV proteins are required for thermostability of PS II and thermal acclimation in Synechocystis sp. PCC 6803 [Kimura et al. (2002) Plant Cell Physiol 43: 932-938]. However, thermostability and thermal acclimation in DeltaPsbP cells were similar to wild type. These results are consistent with the conclusion that PsbP is associated with approximately 3 of PS II centers, and may play a regulatory role in PS II [Thornton et al. (2004) Plant Cell 16: 2164-2175].
sll1418基因在集胞藻PCC 6803中编码一种类PsbP蛋白。sll1418在BG-11培养基以及Cl-或Ca2+限制培养基中的表达相似，并且sll1418的失活并不妨碍在正常或营养限制条件下的光合自养生长。野生型和DeltaPsbP菌株也表现出相似的放氧能力和光系统II（PS II）中心的组装。在DeltaPsbO:DeltaPsbP、DeltaPsbQ:DeltaPsbP、DeltaPsbU:DeltaPsbP和DeltaPsbV:DeltaPsbP突变体中sll1418的失活并不妨碍这些菌株的光合自养能力，也不会改变PS II的组装和放氧。此外，PsbP的缺失并不影响碱性pH恢复DeltaPsbO:DeltaPsbU菌株光合自养生长的能力。PsbO、PsbU和PsbV蛋白是集胞藻PCC 6803中PS II热稳定性和热适应所必需的[Kimura等人（2002年）《植物细胞生理学》43: 932 - 938]。然而，DeltaPsbP细胞中的热稳定性和热适应与野生型相似。这些结果与以下结论一致，即PsbP与大约3个PS II中心相关联，并且可能在PS II中发挥调节作用[Thornton等人（2004年）《植物细胞》16: 2164 - 2175]。
