CO₂ is converted into biomass almost solely by the enzyme rubisco. The poor carboxylation properties of plant rubiscos have led to efforts that made it the most kinetically characterized enzyme, yet these studies focused on < 5% of its natural diversity. Here, we searched for fast‐carboxylating variants by systematically mining genomic and metagenomic data. Approximately 33,000 unique rubisco sequences were identified and clustered into ≈ 1,000 similarity groups. We then synthesized, purified, and biochemically tested the carboxylation rates of 143 representatives, spanning all clusters of form‐II and form‐II/III rubiscos. Most variants (> 100) were active in vitro, with the fastest having a turnover number of 22 ± 1 s⁻¹—sixfold faster than the median plant rubisco and nearly twofold faster than the fastest measured rubisco to date. Unlike rubiscos from plants and cyanobacteria, the fastest variants discovered here are homodimers and exhibit a much simpler folding and activation kinetics. Our pipeline can be utilized to explore the kinetic space of other enzymes of interest, allowing us to get a better view of the biosynthetic potential of the biosphere.

中文翻译：

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通过对自然序列多样性的系统分析发现的高活性红宝石。


CO ₂几乎仅通过rubisco酶转化为生物质。植物红糖苷酶的羧化特性较差，因此人们努力使其成为最具动力学特征的酶，但这些研究集中于其天然多样性的 < 5%。在这里，我们通过系统地挖掘基因组和宏基因组数据来寻找快速羧化变体。大约 33,000 个独特的 rubisco 序列被识别并聚类成约 1,000 个相似组。然后，我们合成、纯化并生化测试了 143 种代表物的羧化率，涵盖了 II 型和 II/III 型 rubiscos 的所有簇。大多数变体（> 100）在体外都有活性，最快的变体周转数为 22 ± 1 s ^-1 - 比植物 Rubisco 中值快六倍，比迄今为止最快测量的 Rubisco 快近两倍。与植物和蓝藻中的红糖不同，这里发现的最快变体是同型二聚体，并且表现出更简单的折叠和激活动力学。我们的管道可用于探索其他感兴趣的酶的动力学空间，使我们能够更好地了解生物圈的生物合成潜力。