Proteorhodopsin （PR） is a recently discovered protein involved in the utilization of light energy. Several studies have shown that PR-containing microorganisms are widespread and compose a large proportion of the bi...Proteorhodopsin （PR） is a recently discovered protein involved in the utilization of light energy. Several studies have shown that PR-containing microorganisms are widespread and compose a large proportion of the biomass in marine ecosystems. A better understanding of the ecological role of PR will help clarify the effect of the global flow of energy and the carbon cycle on marine communities. In this study, a bioinformatical database of PR codon sequences, the Global Distribution Database of Proteorhodopsin （GDDP）, as a tool for analyzing the diversity and distribution of PR-containing microorgan- isms in marine environments throughout the world was designed. The community structure of PR microorganisms were also compared using PCR assays and UniFrac analyses of 12 samples collected from three water layers （0, 75, and 200 m） at four representative sites in the Pacific, Atlantic, and Indian Oceans. The results indicate that PR- containing microorganisms can be grouped into two distribution types： widespread and location-specific. Representative cases of the former include SARll-PR and HOT2C01-PR. Interestingly, PR communities cluster by geographic locale but not by water depth.展开更多
The breakthrough of environmental ge-nomics of marine microbes has revealed the exis-tence of eubacterial rhodopsin in the sea, named proteorhodopsin (PR), which can take light to pro-duce bio-energy for cell metaboli...The breakthrough of environmental ge-nomics of marine microbes has revealed the exis-tence of eubacterial rhodopsin in the sea, named proteorhodopsin (PR), which can take light to pro-duce bio-energy for cell metabolism. Gene and protein sequence analysis and laser flash-induced photolysis experiments have validated the function of PR as light-driven proton-pump. During the pumping process, light energy is transformed into chemical gradient potential across plasma inner-membrane, the potential energy is then used to synthesize ATP. The finding of PR actually brings to light a novel pathway of sunlight utilization existing in heterotro-phic eubacteria in contrast to the well-known chloro-phyll-dependent photosynthesis in the sea. Since the group of PR-bearing bacteria is one of the numeri-cally richest microorganisms on the Earth, accounting for 13% of the total in sea surface water, and with averaged cellular PR molecules of 2.5×104, PR- bearing bacteria are a key component not to be ig-nored in energy metabolism and carbon cycling in the sea. Based on the understanding of current literature and our own investigation on PR in the China seas which indicated a ubiquitous presence and high di-versity of PR in all the marine environments, we propose a conceptual model of energy flow and car-bon cycling driven by both pigment-dependent and -independent biological utilization of light in the ocean.展开更多
文摘Proteorhodopsin （PR） is a recently discovered protein involved in the utilization of light energy. Several studies have shown that PR-containing microorganisms are widespread and compose a large proportion of the biomass in marine ecosystems. A better understanding of the ecological role of PR will help clarify the effect of the global flow of energy and the carbon cycle on marine communities. In this study, a bioinformatical database of PR codon sequences, the Global Distribution Database of Proteorhodopsin （GDDP）, as a tool for analyzing the diversity and distribution of PR-containing microorgan- isms in marine environments throughout the world was designed. The community structure of PR microorganisms were also compared using PCR assays and UniFrac analyses of 12 samples collected from three water layers （0, 75, and 200 m） at four representative sites in the Pacific, Atlantic, and Indian Oceans. The results indicate that PR- containing microorganisms can be grouped into two distribution types： widespread and location-specific. Representative cases of the former include SARll-PR and HOT2C01-PR. Interestingly, PR communities cluster by geographic locale but not by water depth.
基金supported by the National Natural Science Foundation of China(Grant Nos.40232021,40576063&40521003)the Ministry of Science and Technology Projects(Grant Nos.G2000078500,2001CB409700,2003DF000040&2005AA635240).
文摘The breakthrough of environmental ge-nomics of marine microbes has revealed the exis-tence of eubacterial rhodopsin in the sea, named proteorhodopsin (PR), which can take light to pro-duce bio-energy for cell metabolism. Gene and protein sequence analysis and laser flash-induced photolysis experiments have validated the function of PR as light-driven proton-pump. During the pumping process, light energy is transformed into chemical gradient potential across plasma inner-membrane, the potential energy is then used to synthesize ATP. The finding of PR actually brings to light a novel pathway of sunlight utilization existing in heterotro-phic eubacteria in contrast to the well-known chloro-phyll-dependent photosynthesis in the sea. Since the group of PR-bearing bacteria is one of the numeri-cally richest microorganisms on the Earth, accounting for 13% of the total in sea surface water, and with averaged cellular PR molecules of 2.5×104, PR- bearing bacteria are a key component not to be ig-nored in energy metabolism and carbon cycling in the sea. Based on the understanding of current literature and our own investigation on PR in the China seas which indicated a ubiquitous presence and high di-versity of PR in all the marine environments, we propose a conceptual model of energy flow and car-bon cycling driven by both pigment-dependent and -independent biological utilization of light in the ocean.
