研究人员表示，核酮糖-1,5-二磷酸羧化酶/加氧酶（Rubisco）的演化对其底物二氧化碳和不受欢迎的副底物二氧有很强的分辨能力，这是光合生物适应含氧环境的一个重要事件。
研究人员利用祖先的序列重建来重述了这一事件。结果表明，在大气中出现氧气之前，Rubisco通过获得一个附属亚单位提高了其特异性和羧化效率。利用结构和生物化学方法，研究人员追溯了这个亚单位是如何获得并成为必要的。这项工作阐明了对环境氧含量上升的适应性出现，为研究那些因其本质性而一直难以捉摸的相互作用的功能提供了一个模板，并揭示了Rubisco中特异性的决定因素。
附：英文原文
Title: Evolution of increased complexity and specificity at the dawn of form I Rubiscos
Author: Luca Schulz, Zhijun Guo, Jan Zarzycki, Wieland Steinchen, Jan M. Schuller, Thomas Heimerl, Simone Prinz, Oliver Mueller-Cajar, Tobias J. Erb, Georg K. A. Hochberg
Issue&Volume: 2022-10-14
Abstract: The evolution of ribulose-1,5-bisphosphate carboxylase/oxygenases (Rubiscos) that discriminate strongly between their substrate carbon dioxide and the undesired side substrate dioxygen was an important event for photosynthetic organisms adapting to an oxygenated environment. We use ancestral sequence reconstruction to recapitulate this event. We show that Rubisco increased its specificity and carboxylation efficiency through the gain of an accessory subunit before atmospheric oxygen was present. Using structural and biochemical approaches, we retrace how this subunit was gained and became essential. Our work illuminates the emergence of an adaptation to rising ambient oxygen levels, provides a template for investigating the function of interactions that have remained elusive because of their essentiality, and sheds light on the determinants of specificity in Rubisco.
DOI: abq1416
Source: https://www.science.org/doi/10.1126/science.abq1416