内容提要: |
Functions of transcriptional regulators (TRs) are poorly understood in model cyanobacterium Synechocystis sp. PCC 6803. To address the issue, knockout mutants for 32 putative TR encoding genes of Synechocystis are constructed for analyzing their phenotypes under autotrophic condition and metabolic profiles via LC-MS-based metabolomics. Four mutants showed different growth patterns compared with wild type; for the remaining mutants, no growth differences were observed while the metabolomic profiles showed they were visibly different at the metabolite level, suggesting significant functional diversity of TRs in Synechocystis. In addition, an integrative metabolomic and phylogenetic analyses of all TR mutants led to the identification of five pairs of TR genes that each pair shared close relationship in both phylogenetic and metabolomic clustering trees, suggesting possible conserved functions of these TRs during evolution. Moreover, more than a dozen pairs of TR genes with different origin and evolution were found with similar metabolomic profiles, suggesting a possible functional convergence of the TRs during genome evolution. This study provided new insights into the regulatory functions and evolution of TR genes in Synechocystis.
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