ジャーナル: Science / 年: 2022 タイトル: Evolution of increased complexity and specificity at the dawn of form I Rubiscos. 著者: 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 / 要旨: 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 ...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.
A: RubisCO large subunit B: RubisCO large subunit C: RubisCO large subunit D: RubisCO large subunit E: RubisCO large subunit F: RubisCO large subunit G: RubisCO large subunit H: RubisCO large subunit ヘテロ分子
温度: 288 K / 手法: 蒸気拡散法, シッティングドロップ法 / pH: 6.5 詳細: Purified enzyme (5 mg/mL) in 25 mM Tricine-NaOH, 75 mM NaCl, pH 8.0 was incubated at 3% (v/v) CO2 in air and 30 degrees C for 1 h in the presence of 0.2 mM CABP and 3.2 mM MgCl2. The enzyme ...詳細: Purified enzyme (5 mg/mL) in 25 mM Tricine-NaOH, 75 mM NaCl, pH 8.0 was incubated at 3% (v/v) CO2 in air and 30 degrees C for 1 h in the presence of 0.2 mM CABP and 3.2 mM MgCl2. The enzyme was then mixed in a 1:1 ratio with 0.1 M ammonium sulfate, 0.3 M sodium formate, 0.1 M sodium cacodylate , 3% (w/v) gamma-PGA, and 2% (w/v) PEG 3350, pH 6.5. Before flash freezing the crystals in liquid nitrogen PEG200 was added to the mother liquor as cryoprotectant to a final concentration of 40 % (w/v).