Biochimica et Biophysica Acta-Bioenergetics最新文献

Assembly, selectivity, and compatibility of bacterial photosynthetic complexes from divergent species detected in a chimeric strain. 嵌合菌株中不同种类细菌光合复合体的组装、选择性和相容性。

IF 2.7 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2026-01-27 DOI: 10.1016/j.bbabio.2026.149584

Lu Wang, Yi-Hao Yan, Guang-Lei Wang, Xing-Yu Yue, Chen-Hui Qi, Mei-Juan Zou, Zheng-Yu Wang-Otomo, Michael T Madigan, Yueyong Xin, Long-Jiang Yu

Photosynthetic complexes comprising light-harvesting (LH) and reaction center (RC) components are essential for biological energy conversion in photosynthesis. Assembly of these multi-protein structures is a topic of great interest, and assembly mechanisms appear to reflect the evolutionary diversity of the particular phototrophic organism. Here we constructed a photosynthetic chimera expressing the Roseiflexus castenholzii LH and Rhodospirillum rubrum RC complexes in a photocomplex-deficient Rsp. rubrum mutant, and spectroscopy confirmed LH expression with absorption maxima at 878 and 801 nm. The chimeric strain grew slower phototrophically than wildtype but faster than a strain containing only the RC, indicating partial energy transfer from LH to RC. Cryo-EM structural analysis revealed that the Rfl. castenholzii LH independently assembled into a closed ring of 15 αβ heterodimers lacking carotenoids, resulting in a blue-shifted Q_y transition, while the Rsp. rubrum RC formed a separate complex with an RC:LH ratio of ∼17:1 instead of a typical 1:1. Structural differences, including the absence of two Rfl. castenholzii-specific small proteins, likely precluded formation of a conjoined LH-RC in the chimeric strain. These results reveal that distinct photocomplex assembly strategies exist in phylogenetically divergent species and underscore the modularity and adaptability of photosynthetic complexes, offering insights for artificial photosystem design.

由光收集（LH）和反应中心（RC）组成的光合配合物是光合作用中生物能量转化的重要组成部分。这些多蛋白结构的组装是一个非常有趣的话题，组装机制似乎反映了特定光养生物的进化多样性。本研究构建了一个光合嵌合体，在一个光配合物缺乏的Rsp中表达Roseiflexus castenholzii LH和Rhodospirillum rubrum RC复合物。光谱学证实了LH的表达，吸收最大值在878和801 nm处。嵌合菌株的光养生长速度比野生型慢，但比只含RC的菌株快，表明部分能量从LH转移到RC。Cryo-EM结构分析显示Rfl。castenholzii LH独立组装成一个由15个缺乏类胡萝卜素的αβ异源二聚体组成的闭合环，导致蓝移的Qy转变，而Rsp。rubrum RC形成单独的配合物，RC:LH比为~17:1，而不是典型的1:1。结构上的差异，包括缺少两个Rfl。castenholzii特异性小蛋白可能在嵌合菌株中阻止了连体LH-RC的形成。这些结果揭示了在系统发育上不同的物种中存在不同的光复合体组装策略，并强调了光合复合体的模块化和适应性，为人工光系统设计提供了见解。

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引用次数: 0

Recover a long-missing thermodynamic limit from experimental trajectories of F1-ATPase molecular motor 从f1 - atp酶分子马达的实验轨迹中恢复长期缺失的热力学极限

IF 2.7 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2026-01-22 DOI: 10.1016/j.bbabio.2026.149583

Ruizheng Hou , Shoichi Toyabe , Zhisong Wang

In the field of molecular motors, a general thermodynamic limit is widely used in theories but long missing in experiments. By this limit, a motor's forward-to-backward stepping ratio obeys a distinct full-step scaling with an opposing force, and is further related to a thermodynamic force that may inform the motor's stall force and energy efficiency from low-force experiments or even force-independent optical tracking experiments. This limit is now recovered directly from experimental trajectories of F₁-ATPase motor – in a strict ‘double-blind’ test with the thermodynamic force and the stepping ratio extracted independently from the trajectories by an improved statistical method and a rigorous thermodynamic analysis based on Jarzynski equality. This study thus removes a long-standing controversy in the field of molecular motors, and significantly reduces the difficulty of stall force measurement. Notably, this study also enables experimental access to the elusive stepping ratio, which is essentially a ratio of cycle fluxes and hence difficult to measure so far. Finally, the Jarzynski equality-based thermodynamic analysis is comprehensive, providing a unified conceptual framework to analyze evolutionary optimality of biological molecular motors and guide development of artificial molecular motors.

在分子马达领域，一个普遍的热力学极限在理论中被广泛应用，但在实验中却长期缺乏。在这个极限下，电机的前向后步进比在相反的力下服从明显的全步缩放，并且进一步与热力学力相关，该热力学力可以从低力实验甚至力无关的光学跟踪实验中通知电机的失速力和能量效率。该极限现在直接从f1 - atp酶电机的实验轨迹中恢复-在严格的“双盲”测试中，通过改进的统计方法和基于Jarzynski等式的严格热力学分析，从轨迹中独立提取了热力学力和步进比。该研究消除了分子马达领域长期存在的争议，显著降低了失速力测量的难度。值得注意的是，这项研究还使实验获得了难以捉摸的步进比，步进比本质上是周期通量的比率，因此迄今为止难以测量。最后，基于Jarzynski等式的热力学分析是全面的，为分析生物分子马达的进化最优性和指导人工分子马达的开发提供了统一的概念框架。

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引用次数: 0

Utilization of minor red-shifted chlorophyll a for oxygenic photosynthesis under far-red light in green algae 小红移叶绿素a对绿藻远红光下氧光合作用的利用

IF 2.7 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2026-01-17 DOI: 10.1016/j.bbabio.2026.149582

Fei Wang , Seiji Akimoto , Masami Kobayashi , Hideaki Miyashita

Several eukaryotic alga species can perform oxygenic photosynthesis under far-red (FR) light using light-harvesting complexes that absorb this light. We previously isolated a green alga, Neochloris sp. Biwa 5-2, which can grow under FR LED light. However, the mechanisms that support photosynthesis and enable growth under such conditions remain unclear. Here, we performed spectroscopic analyses to investigate light harvesting and excitation-energy transfer in Neochloris sp. Biwa 5-2 under FR light. Two types of minor red-shifted chlorophyll a (Chl a), Chl 706 and Chl 718, were identified as pigments that can absorb light and contribute to oxygenic photosynthesis under FR conditions. Time-resolved fluorescence spectroscopy confirmed that these pigments were involved in excitation-energy transfer via an uphill energy transfer process. During this process, Neochloris sp. Biwa 5-2 uses constitutively present minor red-shifted Chl a to harvest FR light and sustain photosynthesis. This study appears to be the first report of minor Chl a functioning as a primary light-harvesting pigment that enables growth under FR light.

几种真核藻类可以在远红光（FR）光下进行含氧光合作用，利用吸收这种光的光收集复合物。我们之前分离出一种绿藻，Neochloris sp. Biwa 5-2，它可以在FR LED灯下生长。然而，在这种条件下支持光合作用和促进生长的机制仍不清楚。本文通过光谱分析研究了新绿藻（Neochloris sp. Biwa 5-2）在FR光下的光收集和激发-能量传递。两种小红移叶绿素a (Chl a) Chl 706和Chl 718被鉴定为在FR条件下能够吸收光并参与含氧光合作用的色素。时间分辨荧光光谱证实了这些色素通过上坡的能量传递过程参与了激发-能量传递。在这一过程中，琵琶鱼5-2利用组成性存在的少量红移Chl a来收获FR光并维持光合作用。这项研究似乎是第一次报道小Chl - a作为一种主要的光收集色素，使其能够在FR光下生长。

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引用次数: 0

Quantitative decomposition of non-photochemical quenching in Physcomitrium patens highlights synergistic roles of LhcSR and zeaxanthin 非光化学猝灭的定量分解表明LhcSR和玉米黄质具有协同作用。

IF 2.7 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2026-01-15 DOI: 10.1016/j.bbabio.2026.149581

Cleo Bagchus , Lennart A.I. Ramakers , Dana Verhoeven , Claudia Beraldo , Alessandro Alboresi , Tomas Morosinotto , Herbert van Amerongen , Emilie Wientjes

Non-photochemical quenching (NPQ) is a collective term for photoprotective processes that safely dissipate excess light energy as heat. The moss Physcomitrium patens is an interesting species for the study of NPQ as it contains PsbS (indispensable for NPQ in vascular plants), LhcSR (indispensable for NPQ in green algae) and a xanthophyll cycle, which interconverts violaxanthin (Vx) and zeaxanthin (Zx) and is also imperative for NPQ. Here, we aimed to disentangle the individual contributions of PsbS, LhcSR and Zx to NPQ. NPQ induction and relaxation were measured for wild-type P. patens and thirteen mutants with altered NPQ at a wide range of light intensities. We applied a multivariate data analysis pipeline to find distinct kinetic components underlying NPQ, together with their contributions to NPQ. A slowly-rising component provides most NPQ, especially at higher light intensities. Another component contains a transient NPQ peak with a fast rise, providing quick protection, and requires the presence of either PsbS or LhcSR. Both components are enhanced by the combined presence of Zx and LhcSR. While PsbS-related NPQ is less dependent on Zx, in contrast to the situation in vascular plants, Vx to Zx conversion enhances LhcSR-related NPQ at all light intensities and within the first minute of illumination. The influence of Zx is thus broader than previously recognized, especially through its synergistic interaction with LhcSR.

非光化学猝灭（NPQ）是光保护过程的总称，它可以安全地将多余的光能以热的形式消散。苔藓Physcomitrium patens是研究NPQ的一个有趣物种，因为它含有PsbS（维管植物中NPQ所必需的）、LhcSR（绿藻中NPQ所必需的）和叶黄素循环，它可以相互转化紫黄质（Vx）和玉米黄质（Zx），也是NPQ所必需的。在这里，我们旨在理清psb、LhcSR和Zx对NPQ的个人贡献。研究了野生型和13个NPQ改变突变体在大范围光强下的NPQ诱导和松弛。我们应用多元数据分析管道来发现NPQ背后不同的动力学成分，以及它们对NPQ的贡献。缓慢上升的分量提供了大部分NPQ，特别是在较高的光强下。另一个组件包含一个快速上升的瞬态NPQ峰值，提供快速保护，并且需要psb或LhcSR的存在。Zx和LhcSR的联合存在增强了这两种成分。虽然pbs相关的NPQ对Zx的依赖性较小，但与维管植物相比，Vx到Zx的转换在所有光强和照明的第一分钟内都增强了lhcsr相关的NPQ。因此，Zx的影响比以前认识到的更广泛，特别是通过它与LhcSR的协同相互作用。

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引用次数: 0

Substitution of Mg2+ cofactor with Ca2+ disrupts positive cooperativity in F1FO-ATP(hydrol)ase catalysis Ca2+取代Mg2+辅助因子破坏了F1FO-ATP（水解）酶催化的正协同性

IF 2.7 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2026-01-09 DOI: 10.1016/j.bbabio.2025.149580

Cristina Algieri , Antonia Cugliari , Fabiana Trombetti , Salvatore Nesci

The mitochondrial F₁F_O-ATPase is a dual-function enzyme that synthesizes ATP using the proton motive force and hydrolyzes ATP to reenergize the membrane.

Mg²⁺ is the physiological cofactor of F₁F_O-ATPase, enabling both ATP synthesis and hydrolysis, while Ca²⁺ supports only ATP hydrolysis.

Mg²⁺-dependent F₁F_O-ATPase exhibits positive cooperativity in ATP hydrolysis Hill coefficient (nHi) of 2.01 ± 0.21, whereas Ca²⁺-dependent activity shows Michaelian kinetics, nHi 1.41 ± 0.06.

Ca²⁺ acts as an uncompetitive inhibitor on Mg²⁺-dependent ATP hydrolysis, suggesting distinct binding sites and conformational effects.

The differential kinetic behavior underlies the enzyme's multifunctionality of F₁F_O-ATPase in physio-pathological conditions, depending on the cofactor.

线粒体f1fo -ATP酶是一种双功能酶，它利用质子动力合成ATP，并水解ATP使膜重新通电。Mg2+是f1fo -ATP酶的生理辅助因子，既能合成ATP又能水解ATP，而Ca2+只支持ATP水解。Mg2+依赖性f1fo -ATP酶在ATP水解过程中表现出正协同性，希尔系数（nHi）为2.01±0.21，而Ca2+依赖性f1fo -ATP酶的希尔系数（nHi）为1.41±0.06。Ca2+作为Mg2+依赖性ATP水解的非竞争性抑制剂，提示不同的结合位点和构象影响。不同的动力学行为是f1fo - atp酶在生理病理条件下的多功能性的基础，这取决于辅助因子。

引用次数: 0

A red-shifted LHCII in Chlamydomonas priscui allows for efficient light harvesting under an Antarctic lake 普里斯崔衣藻中的红移LHCII允许在南极湖泊下有效地收集光线。

IF 2.7 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2025-12-23 DOI: 10.1016/j.bbabio.2025.149579

Sam Wilson , Jun Minagawa

The psychrophilic green alga Chlamydomonas priscui was isolated from an Antarctic lake, where it has adapted to low light, low temperature, and high salinity environment. How photosynthetic light harvesting adjusts to such conditions remains an important question. Here, we present biochemical, biophysical, and phylogenetic analyses of the major light-harvesting complex II (LHCII) of C. priscui (CpLHCII). Compared to the LHCII of the mesophilic model alga C. reinhardtii (CrLHCII), CpLHCII has a chlorophyll (Chl) a:b ratio of ~1 (CrLHCII Chl a:b = ~1.24), with an intermediate red Chl a species replaced by Chl b and altered spectral tuning of Chl a. These changes cause an overall red shift in absorption, apparently driven by specific mutations in the primary sequence of CpLHCII. Consequently, CpLHCII shows enhanced energy transfer efficiency, in particular for energy harvested in the blue-green region directed to Chl a. These characteristics indicate a light-harvesting system with reduced energy loss, with respect to CrLHCII. We propose that the unique properties of CpLHCII aids survival in the extreme, spectrally-limited light conditions posed by C. priscui's ecological niche and suggest that these features could inform strategies to optimize light harvesting in agriculture and biotechnology.

从南极湖泊中分离出了一种适应了弱光、低温和高盐度环境的嗜冷绿藻——普里崔衣藻。光合作用的光收集如何适应这样的条件仍然是一个重要的问题。在这里，我们介绍了C. priscui （CpLHCII）的主要光收集复合物II （LHCII）的生化、生物物理和系统发育分析。与中温模式藻C. reinhardtii （CrLHCII）的LHCII相比，CpLHCII的叶绿素（Chl） a:b比值为~1 (CrLHCII Chl a:b = ~1.24)，中间红色的Chl a种被Chl b取代，Chl a的光谱调谐发生改变。这些变化引起了吸收的整体红移，显然是由CpLHCII一级序列的特定突变驱动的。因此，CpLHCII显示出更高的能量转移效率，特别是在蓝绿色区域收集到Chl a的能量。这些特征表明，与CrLHCII相比，CpLHCII的光收集系统具有更低的能量损失。我们认为CpLHCII的独特特性有助于C. priscui生态位造成的极端、光谱有限的光条件下的生存，并建议这些特性可以为优化农业和生物技术的光收集策略提供信息。

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引用次数: 0

The contribution of D2-Arg265 to the molecular architecture of the quinone-Fe-bicarbonate acceptor complex of photosystem II D2-Arg265对光系统II中醌-碳酸氢铁受体复合物分子结构的贡献。

IF 2.7 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2025-12-21 DOI: 10.1016/j.bbabio.2025.149578

Victor Zhong , Imre Vass , Julian J. Eaton-Rye

In Photosystem II (PS II) the D2 and D1 proteins provide binding sites for the primary (Q_A) and secondary (Q_B) plastoquinone electron acceptors, respectively. A non-heme iron is located between Q_A and Q_B that is coordinated by a bicarbonate ligand and two His residues from D1 (D1-His215 and D1-His272) and two His residues from D2 (D2-His214 and D2-His268). The symmetry of the quinone-Fe-acceptor complex extends to D1-Arg269, which has hydrogen bonds to D1-His272, and D2-Arg265 which has hydrogen bonds to D2-His268. We have examined the role of D2-Arg265 by creating the R265A and R265D mutants in the cyanobacterium Synechocystis sp. PCC 6803. Both mutants exhibited normal photoautotrophic growth, but showed a reduction in oxygen evolution in the presence of the PS II-specific electron acceptor 2,5-dimethyl-1,4-benzoquinone (DMBQ). Chlorophyll a fluorescence induction and decay kinetics were also inhibited in the presence of DMBQ and, in the presence of the native quinone, revealed slowed Q_A⁻ to Q_B electron transfer, together with impaired exchange between the Q_B-binding site and the plastoquinone pool. Addition of formate further inhibited electron transfer, consistent with weakened bicarbonate binding in the mutants, and thermoluminescence measurements revealed a decreased redox gap between Q_A and Q_B. Additionally, both mutants displayed heightened sensitivity to high light. These findings demonstrate that D2-Arg265 is important for stability of the acceptor side, bicarbonate-dependent electron transfer, and an optimal Q_B-binding site. All of our results are also consistent with the architecture of the quinone-Fe-bicarbonate complex supporting photoprotection and regulatory roles that are unique to oxygenic photosynthesis.

在光系统II （PS II）中，D2和D1蛋白分别为初级（QA）和次级（QB）质体醌电子受体提供结合位点。一个非血红素铁位于QA和QB之间，由一个碳酸氢盐配体和两个来自D1的His残基（D1- his215和D1- his272）和两个来自D2的His残基（D2- his214和D2- his268）协调。醌-铁受体配合物的对称性扩展到D1-Arg269和D2-Arg265，前者与D1-His272有氢键，后者与D2-His268有氢键。我们通过在蓝细菌聚囊藻sp. PCC 6803中创建R265A和R265D突变体来检测D2-Arg265的作用。两个突变体都表现出正常的光自养生长，但在PS ii特异性电子受体2,5-二甲基-1,4-苯醌（DMBQ）的存在下，氧释放减少。在DMBQ的存在下，叶绿素a的荧光诱导和衰减动力学也受到抑制，而在天然醌的存在下，QA-到QB的电子转移减慢，QB结合位点和质体醌池之间的交换受损。甲酸的加入进一步抑制了电子转移，这与突变体中碳酸氢盐结合减弱一致，热释光测量显示QA和QB之间的氧化还原间隙减小。此外，这两种突变体对强光表现出更高的敏感性。这些发现表明D2-Arg265对于受体侧的稳定性、碳酸氢盐依赖的电子转移和最佳的qb结合位点很重要。我们所有的研究结果也与醌-碳酸氢铁复合物的结构一致，该复合物支持光保护和氧光合作用特有的调节作用。

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引用次数: 0

Thermodynamic landscape of the redox-centres in the electron-confurcating [FeFe]-Hydrogenase (TmHydABC) of Thermotoga maritima 海洋热藻（Thermotoga martima）电子构型[FeFe]-氢化酶（TmHydABC）氧化还原中心的热力学景观。

IF 2.7 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2025-12-19 DOI: 10.1016/j.bbabio.2025.149577

Kilian Zuchan , Nina Breuer , Christoph Laurich , Wolfgang Nitschke , Frauke Baymann , James A. Birrell

The heterotrimeric [FeFe]‑hydrogenase (TmHydABC) from Thermotoga maritima synergistically uses electrons from ferredoxin and NADH to reduce protons to hydrogen enabling the anaerobic metabolism of carbohydrates and other molecules. The precise mechanism by which this flavin-based electron confurcation is achieved is still unknown. Here, the redox properties of the cofactors in TmHydABC were characterized via chemical and electrochemical redox titrations monitored by EPR- and UV/Vis-spectroscopy. Deconvolution of nine out of eleven iron‑sulfur clusters harboured by the apo-enzyme was achieved by (a) exploiting the distinct relaxation properties (and hence temperature-dependencies) of the EPR-signals, (b) making use of spectral idiosyncrasies of [4Fe-4S] versus thioredoxin-like [2Fe-2S] clusters in UV/Vis-spectroscopy and (c) using the individual HydA, HydB and HydC subunits and C-terminal domains of HydA and HydB. Furthermore, electrostatic interactions between certain neighbouring clusters and a paramagnetic interaction between the flavin and one of the iron‑sulfur clusters were revealed. The electrochemical parameters of the flavin were obtained both via UV/Vis-spectroscopy and EPR-analysis of its semi-reduced state in isolated HydB. This semi-reduced state was found to correspond to a neutral flavosemiquinone and a pK_a (attributed to the N5-proton) was extracted from the pH-dependence of its redox midpoint potential. The electrochemical properties of the flavin in the entire enzyme appear to differ significantly from those in the isolated HydB subunit. The flavin and iron‑sulfur cluster redox properties indicate a dynamic electrochemical landscape, potentially contributing to its mechanism.

来自Thermotoga martima的异三聚体[FeFe]氢化酶（TmHydABC）协同利用来自铁氧还蛋白和NADH的电子将质子还原为氢，从而实现碳水化合物和其他分子的厌氧代谢。这种基于黄素的电子构型实现的精确机制仍然未知。通过化学和电化学氧化还原滴定，利用EPR-和紫外/可见光谱对TmHydABC中辅因子的氧化还原特性进行了表征。通过(a)利用epr信号的不同弛豫特性（以及温度依赖性），(b)利用[4Fe-4S]与类硫氧还蛋白[2Fe2S]簇在紫外/可见光谱中的光谱特性，以及(c)利用单个HydA， HydB和HydC亚基以及HydA和HydB的c端结构域，实现了载酶所包含的11个铁硫簇中的9个的反卷积。此外，还发现了相邻簇簇之间的静电相互作用以及黄素与其中一个铁硫簇簇之间的顺磁相互作用。通过紫外/可见光谱和epr对分离的HydB进行半还原态分析，得到了黄素的电化学参数。发现这种半还原状态对应于中性黄酮半醌，并从其氧化还原中点电位的ph依赖性中提取了pKa（归因于n5质子）。整个酶中黄素的电化学性质似乎与分离的HydB亚基中的黄素有很大不同。黄素和铁硫簇氧化还原性质表明了一个动态的电化学景观，可能有助于其机制。

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引用次数: 0

Energetics and evolution: Response to Martin 能量学和进化：对马丁的回应。

IF 2.7 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2025-12-17 DOI: 10.1016/j.bbabio.2025.149576

Michael Lynch

A recent paper in this journal claims that prior estimates of the bioenergetic costs of producing cells are off by more than 100-fold. Here, it is shown that this conclusion is based on an erroneous interpretation of the methods previously employed by a diversity of authors and that the downstream arguments are conceptually flawed. Likewise, the author's claim that the establishment of the mitochondrion caused a quantum leap in bioenergetic capacity that spurred a revolution in eukaryotic innovation is inconsistent with empirical data and evolutionary theory.

该杂志最近发表的一篇论文称，之前对生产细胞的生物能源成本的估计误差超过100倍。本文表明，这一结论是基于对不同作者以前使用的方法的错误解释，而下游论点在概念上是有缺陷的。同样，作者声称线粒体的建立导致了生物能量能力的巨大飞跃，从而引发了真核生物创新的革命，这与经验数据和进化理论不一致。

引用次数: 0

Oxygen reductase origin followed the great oxidation event and terminated the Lomagundi excursion 氧还原酶起源于大氧化事件，终止了Lomagundi旅行。

IF 2.7 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2025-12-01 DOI: 10.1016/j.bbabio.2025.149575

Katharina Trost , Robert B. Gennis , John F. Allen , Daniel B. Mills , William F. Martin

The history of Earth's atmospheric oxygen is a cornerstone of evolutionary biology. While unequivocal evidence for an increase in atmospheric O₂ marks the Great Oxidation Event (GOE) roughly 2.4 billion years ago, evidence underlying proposals for pre-GOE O₂ accumulation is debated. Here we have investigated the distribution of genes for oxygen reductases, the enzymes that consume O₂ in respiratory chains, across independently generated molecular timescales of prokaryotic evolution. The data indicate that cytochrome bd-oxidases, heme-copper oxidases and alternative oxidases arose in the wake of the GOE ca. 2.4 billion years ago, after which the genes were subjected to abundant lateral gene transfer, a reflection of their utility in redox balance and membrane bioenergetics. The data lead us to propose a straightforward four-stage model for O₂ accumulation surrounding the GOE: (i) Negligible O₂ existed prior to the GOE. (ii) Cyanobacterial O₂ production started at the GOE, yet was capped at 2 % [v/v] atmospheric O₂, the threshold at which cyanobacterial nitrogenase is inhibited by O₂. (iii) Production of 0.02 atm of O₂ (2 % [v/v]) at the GOE buried roughly the entire atmospheric CO₂ inventory, causing sudden enrichment of ¹³C in dissolved inorganic carbon (the Lomagundi ¹³C anomaly), through RuBisCO isotope discrimination, without atmospheric O₂ exceeding 2 % [v/v]. (iv) High atmospheric ¹²C at the end of the Lomagundi excursion marks the origin of oxygen reductases, their rapid spread via function in respiratory CO₂ liberation, and the onset of equilibrium between photosynthetic O₂ production and respiratory O₂ consumption at 2 % atmospheric O₂.

地球大气中氧气的历史是进化生物学的基石。虽然明确的证据表明大气中O2的增加标志着大约24亿年前的大氧化事件（GOE），但关于GOE之前O2积累的证据存在争议。在这里，我们研究了氧还原酶基因的分布，氧还原酶是在呼吸链中消耗氧气的酶，在原核生物进化的独立产生的分子时间尺度上。这些数据表明，细胞色素b -氧化酶、血红素铜氧化酶和替代氧化酶是在大约24亿年前的GOE之后出现的，之后这些基因经历了大量的横向基因转移，这反映了它们在氧化还原平衡和膜生物能量学中的作用。根据这些数据，我们提出了一个简单的四阶段GOE周围O2积累模型：(i)在GOE之前存在可忽略的O2。（ii）蓝藻的O2生产始于GOE，但被限制在2 % [v/v]大气O2，这是蓝藻的氮酶被O2抑制的阈值。（iii）通过RuBisCO同位素判别，在大气O2不超过2 % [v/v]的情况下，GOE产生的0.02 atm O2（2 % [v/v]）大致埋藏了整个大气CO2库存，导致溶解无机碳中13C的突然富集（Lomagundi 13C异常）。（iv） Lomagundi游结束时的高大气温度12C标志着氧还原酶的起源，它们通过呼吸CO2释放的功能迅速传播，以及在大气O2浓度为2 %时光合O2产生和呼吸O2消耗之间的平衡开始。

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引用次数: 0