抄録
Living organisms respond to phosphate limitation by expressing various genes whose products maintain an appropriate range of phosphate concentrations within each cell. We identified a two-component system, which consists of histidine kinase Hik7 and its cognate response regulator Rre29, that was the dominant sensory system that controled gene expression in response to phosphate limitation in the cyanobacterium Synechocystis sp. PCC 6803.
The response regulators PhoB in E. coli and PhoP in B. subtilis bind specifically to conserved sequences, known as Pho boxes. In order to investigate the possibility that Synechocystis might also have a Pho box, we examined whether Rre29 can bind to the upstream flanking regions of the phosphate limitation-inducible genes. We found that Rre29 bound to the upstream flanking regions of several phosphate limitation-inducible genes at repetitive PyTTAAPyPy(T/A)-like sequences, suggesting that this repetitive sequence might be the Pho box in Synechocystis .
