Biochemical characterization of predicted Precambrian RuBisCO.
Biochemical characterization of predicted Precambrian RuBisCO.
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DOI：
10.1038/ncomms10382
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发表时间：
2016-01-21
影响因子：
16.6
通讯作者：
Kerfeld CA
中科院分区：
文献类型：
--
作者：
Shih PM;Occhialini A;Cameron JC;Andralojc PJ;Parry MA;Kerfeld CA
The antiquity and global abundance of the enzyme, RuBisCO, attests to the crucial and longstanding role it has played in the biogeochemical cycles of Earth over billions of years. The counterproductive oxygenase activity of RuBisCO has persisted over billions of years of evolution, despite its competition with the carboxylase activity necessary for carbon fixation, yet hypotheses regarding the selective pressures governing RuBisCO evolution have been limited to speculation. Here we report the resurrection and biochemical characterization of ancestral RuBisCOs, dating back to over one billion years ago (Gyr ago). Our findings provide an ancient point of reference revealing divergent evolutionary paths taken by eukaryotic homologues towards improved specificity for CO2, versus the evolutionary emphasis on increased rates of carboxylation observed in bacterial homologues. Consistent with these distinctions, in vivo analysis reveals the propensity of ancestral RuBisCO to be encapsulated into modern-day carboxysomes, bacterial organelles central to the cyanobacterial CO2 concentrating mechanism. The enzyme RuBisCO has evolved over billions of years and catalyses reactions in plants and bacteria, although why some reactions persist is unclear. Here, the authors resurrect ancestral RuBisCO to reveal aspects of the Precambrian atmosphere and the selective pressures governing RuBisCO evolution.
