The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, Kraków 30-239, Poland.
Institute of Botany, Jagiellonian University, Gronostajowa 9, Kraków 30-387, Poland.
Bioessays. 2017 Nov;39(11). doi: 10.1002/bies.201700071. Epub 2017 Oct 4.
RubisCO (D-ribulose 1,5-bisphosphate carboxylase/oxygenase) is Earth's main enzyme responsible for CO fixation via carboxylation of ribulose-1,5-bisphosphate (RuBP) into organic matter. Besides the carboxylation reaction, RubisCO also catalyzes the oxygenation of RuBP by O , which is probably as old as its carboxylation properties. Based on molecular phylogeny, the occurrence of the reactive oxygen species (ROS)-removing system and kinetic properties of different RubisCO forms, we postulated that RubisCO oxygenase activity appeared in local microoxic areas, yet before the appearance of oxygenic photosynthesis. Here, in reviewing the literature, we present a novel hypothesis: the RubisCO early oxygenase activity hypothesis. This hypothesis may be compared with the exaptation hypothesis, according to which latent RubisCO oxygenase properties emerged later during the oxygenation of the Earth's atmosphere. The reconstruction of ancestral RubisCO forms using ancestral sequence reconstruction (ASR) techniques, as a promising way for testing of RubisCO early oxygenase activity hypothesis, is presented.
核酮糖-1,5-二磷酸羧化酶/加氧酶（RubisCO）是地球上主要的酶，通过羧化核酮糖-1,5-二磷酸（RuBP）将 CO2 固定成有机物质。除了羧化反应，RubisCO 还可以催化 RuBP 的加氧反应，这可能与其羧化特性一样古老。基于分子系统发育、活性氧（ROS）清除系统的发生和不同 RubisCO 形式的动力学特性，我们推测 RubisCO 加氧酶活性出现在局部微氧区域，但在有氧光合作用出现之前。在这里，我们在回顾文献的基础上，提出了一个新的假设：RubisCO 早期加氧酶活性假说。根据该假说，RubisCO 潜在的加氧酶特性可能是在地球大气氧化过程中后来才出现的。使用祖先序列重建（ASR）技术重建祖先 RubisCO 形式，作为检验 RubisCO 早期加氧酶活性假说的一种有前途的方法，也被提出。
