Jeanjean Robert, Zuther Ellen, Yeremenko Nataliya, Havaux Michel, Matthijs Hans C P, Hagemann Martin
LCB-CNRS, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
FEBS Lett. 2003 Aug 14;549(1-3):52-6. doi: 10.1016/s0014-5793(03)00769-5.
A psaFJ-null mutant of Synechocystis sp. strain PCC 6803 was characterised. As opposed to similar mutants in chloroplasts of green algae, electron transfer from plastocyanin to photosystem 1 was not affected. Instead, a restraint in full chain photosynthetic electron transfer was correlated to malfunction of photosystem 1 at its stromal side. Our hypothesis is that absence of PsaF causes oxidative stress, which triggers the induction of the 'iron stress inducible' operon isiAB. Products are the IsiA chlorophyll-binding protein (CP43') and the isiB gene product flavodoxin. Supporting evidence was obtained by similar isiAB induction in wild type cells artificially exposed to oxidative stress.
对集胞藻6803株系的psaFJ基因缺失突变体进行了表征。与绿藻叶绿体中的类似突变体不同，从质体蓝素到光系统1的电子转移未受影响。相反，全链光合电子转移的抑制与光系统1在其基质侧的功能障碍相关。我们的假设是，PsaF的缺失会导致氧化应激，从而触发“铁应激诱导”操纵子isiAB的诱导。其产物是IsiA叶绿素结合蛋白（CP43'）和isiB基因产物黄素氧还蛋白。通过在人工暴露于氧化应激的野生型细胞中进行类似的isiAB诱导获得了支持证据。
