Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Russia.
A.N. Belozersky Institute of Physical-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.
FEBS Lett. 2014 Nov 28;588(23):4364-8. doi: 10.1016/j.febslet.2014.10.003. Epub 2014 Oct 13.
O2 reduction was investigated in photosystem I (PSI) complexes isolated from cyanobacteria Synechocystis sp. PCC 6803 wild type (WT) and menB mutant strain, which is unable to synthesize phylloquinone and contains plastoquinone at the quinone-binding site A1. PSI complexes from WT and menB mutant exhibited different dependencies of O2 reduction on light intensity, namely, the values of O2 reduction rate in WT did not reach saturation at high intensities, in contrast to the values in menB mutant. The obtained results suggest the immediate phylloquinone involvement in the light-induced O2 reduction by PSI.
我们研究了来源于蓝藻集胞藻 PCC 6803 的野生型（WT）和 menB 突变体菌株的光系统 I（PSI）复合物中的 O2 还原。menB 突变体无法合成叶绿醌，而在醌结合位点 A1 处含有质体醌。WT 和 menB 突变体的 PSI 复合物对光强度的 O2 还原依赖性不同，即在高光照强度下，WT 的 O2 还原速率值没有达到饱和，而 menB 突变体的 O2 还原速率值则达到了饱和。这些结果表明，叶绿醌直接参与 PSI 的光诱导 O2 还原。
