Department of Biology, University of Oxford, Oxford OX1 3RB, United Kingdom.
Proc Natl Acad Sci U S A. 2024 Mar 12;121(11):e2321050121. doi: 10.1073/pnas.2321050121. Epub 2024 Mar 5.
Rubisco is the primary entry point for carbon into the biosphere. However, rubisco is widely regarded as inefficient leading many to question whether the enzyme can adapt to become a better catalyst. Through a phylogenetic investigation of the molecular and kinetic evolution of Form I rubisco we uncover the evolutionary trajectory of rubisco kinetic evolution in angiosperms. We show that is among the 1% of slowest-evolving genes and enzymes on Earth, accumulating one nucleotide substitution every 0.9 My and one amino acid mutation every 7.2 My. Despite this, rubisco catalysis has been continually evolving toward improved CO/O specificity, carboxylase turnover, and carboxylation efficiency. Consistent with this kinetic adaptation, increased rubisco evolution has led to a concomitant improvement in leaf-level CO assimilation. Thus, rubisco has been slowly but continually evolving toward improved catalytic efficiency and CO assimilation in plants.
核酮糖 1,5-二磷酸羧化酶/加氧酶（Rubisco）是碳进入生物圈的主要入口。然而，Rubisco 被广泛认为效率低下，这使得许多人质疑该酶是否能够适应并成为更好的催化剂。通过对 I 型 Rubisco 的分子和动力学进化进行系统发育研究，我们揭示了被子植物 Rubisco 动力学进化的轨迹。我们表明，Rubisco 是地球上进化最慢的基因和酶之一，每 0.9 百万年积累一个核苷酸替换，每 7.2 百万年积累一个氨基酸突变。尽管如此，Rubisco 的催化作用一直在不断进化，以提高 CO/O 特异性、羧化酶周转率和羧化效率。与这种动力学适应一致，Rubisco 的进化增加导致叶片水平 CO2 同化的相应改善。因此，Rubisco 一直在缓慢但持续地进化，以提高植物的催化效率和 CO2 同化。
