title: A novel periplasmic protein (Slr0280) tunes photomixotrophic growth of the cyanobacterium, Synechocystis sp. PCC 6803.
abstract: Cyanobacteria are among the main contributors to global photosynthesis and show a high degree of metabolic plasticity. Synechocystis sp. PCC 6803 can grow under photoautotrophic, photomixotrophic or photoheterotrophic conditions. We have characterized a novel periplasmic protein (Slr0280) that tunes the photomixotrophic growth of Synechocystis sp. PCC 6803. Slr0280 is a multi-domain protein consisting mainly of β-sheets. Several proteins that interact with Slr0280 were identified via bacterial two-hybrid screening. Slr0280 may interact through its DUF2233 domain with partners that participate in sugar metabolism, thereby coordinating the respective regulations. When slr0280 was deleted, the mutant grew more slowly than wild-type in the presence of glucose, which is ascribed to the down-regulation of glycolysis, glycogen catabolism, oxidative pentose phosphate pathway, Calvin cycle and glucose utilization. A positive regulation of Slr0280 on these sugar catabolic enzymes was confirmed by transcript (qPCR) analyses. Based on these findings, we proposed a speculative model that Slr0280 plays a coordinating regulatory role in sugar metabolism.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P.R. China.
authors.forename: Liang-Liang
authors.initials: LL
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P.R. China.
authors.forename: Qing-Dong
authors.initials: QD
authors.lastname: Li
authors.affiliation: iHuman Institute, ShanghaiTech University, Shanghai 201210, P.R. China.
authors.forename: Dong
authors.initials: D
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P.R. China.
authors.forename: Ya-Fang
authors.initials: YF
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P.R. China.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P.R. China. Electronic address: khzhao@163.com.
authors.forename: Kai-Hong
authors.initials: KH
authors.lastname: Zhao
mesh_terms: D005947:Glucose / Q000235:genetics / Q000378:metabolism; D006003:Glycogen / Q000235:genetics / Q000378:metabolism; D006019:Glycolysis / Q000502:physiology*; D010427:Pentose Phosphate Pathway / Q000502:physiology*; D033903:Periplasmic Proteins / Q000235:genetics / Q000378:metabolism; D010788:Photosynthesis / Q000502:physiology*; D017433:Protein Structure, Secondary; D046939:Synechocystis / Q000235:genetics / Q000378:metabolism
chemical_list: D033903:Periplasmic Proteins; D006003:Glycogen; D005947:Glucose
keywords: Carbohydrate metabolism; Cyanobacteria; DUF2233; Photomixotrophic growth; Synechocystis