title: Functional Diversity of Transcriptional Regulators in the CyanobacteriumSynechocystissp. PCC 6803.
abstract: Functions of transcriptional regulators (TRs) are still poorly understood in the model cyanobacteriumSynechocystissp. PCC 6803. To address the issue, we constructed knockout mutants for 32 putative TR-encoding genes ofSynechocystis, and comparatively analyzed their phenotypes under autotrophic growth condition and metabolic profiles using liquid chromatography-mass spectrometry-based metabolomics. The results showed that only four mutants of TR genes,sll1872(lytR),slr0741(phoU),slr0395(ntcB), andslr1871(pirR), showed differential growth patterns in BG11 medium when compared with the wild type; however, in spite of no growth difference observed for the remaining TR mutants, metabolomic profiling showed that they were different at the metabolite level, suggesting significant functional diversity of TRs inSynechocystis. In addition, an integrative metabolomic and gene families' analysis of all TR mutants led to the identification of five pairs of TR genes that each shared close relationship in both gene families 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. Finally, a protein-protein network analysis was performed to predict regulatory targets of TRs, allowing inference of possible regulatory gene targets for 4 out of five pairs of TRs. This study provided new insights into the regulatory functions and evolution of TR genes inSynechocystis.
authors.affiliation: Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin UniversityTianjin, China; Key Laboratory of Systems Bioengineering - Ministry of Education, Tianjin UniversityTianjin, China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and EngineeringTianjin, China.
authors.forename: Mengliang
authors.initials: M
authors.lastname: Shi
authors.affiliation: Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin UniversityTianjin, China; Key Laboratory of Systems Bioengineering - Ministry of Education, Tianjin UniversityTianjin, China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and EngineeringTianjin, China.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin UniversityTianjin, China; Key Laboratory of Systems Bioengineering - Ministry of Education, Tianjin UniversityTianjin, China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and EngineeringTianjin, China.
authors.forename: Guangsheng
authors.initials: G
authors.lastname: Pei
authors.affiliation: Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin UniversityTianjin, China; Key Laboratory of Systems Bioengineering - Ministry of Education, Tianjin UniversityTianjin, China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and EngineeringTianjin, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.affiliation: Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin UniversityTianjin, China; Key Laboratory of Systems Bioengineering - Ministry of Education, Tianjin UniversityTianjin, China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and EngineeringTianjin, China; Center for Biosafety Research and Strategy, Tianjin UniversityTianjin, China.
authors.forename: Weiwen
authors.initials: W
authors.lastname: Zhang
keywords: LC-MS; Synechocystis; function; metabolomics; transcriptional regulators