Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Structure. 2024 Nov 7;32(11):1963-1972.e3. doi: 10.1016/j.str.2024.08.011. Epub 2024 Sep 11.
Enzymes of the 2-oxoacid:ferredoxin oxidoreductase (OFOR) superfamily catalyze the reversible oxidation of 2-oxoacids to acyl-coenzyme A esters and carbon dioxide (CO)using ferredoxin or flavodoxin as the redox partner. Although members of the family share primary sequence identity, a variety of domain and subunit arrangements are known. Here, we characterize the structure of a four-subunit family member: the pyruvate:ferredoxin oxidoreductase (PFOR) from the methane producing archaeon Methanosarcina acetivorans (MaPFOR). The 1.92 Å resolution crystal structure of MaPFOR shows a protein fold like those of single- or two-subunit PFORs that function in 2-oxoacid oxidation, including the location of the requisite thiamine pyrophosphate (TPP), and three [4Fe-4S] clusters. Of note, MaPFOR typically functions in the CO reductive direction, and structural comparisons to the pyruvate oxidizing PFORs show subtle differences in several regions of catalytical relevance. These studies provide a framework that may shed light on the biochemical mechanisms used to facilitate reductive pyruvate synthesis.
2- 酮酸：铁氧还蛋白氧化还原酶（OFR）超家族的酶催化 2- 酮酸可逆氧化为酰基辅酶 A 酯和二氧化碳（CO），使用铁氧还蛋白或黄素氧还蛋白作为氧化还原伴侣。尽管该家族的成员具有一级序列同一性，但已知存在各种结构域和亚基排列。在这里，我们描述了一种四亚基家族成员的结构：产甲烷古菌 Methanosarcina acetivorans（MaPFOR）中的丙酮酸：铁氧还蛋白氧化还原酶（PFOR）。MaPFOR 的 1.92 Å 分辨率晶体结构显示出类似于在 2- 酮酸氧化中起作用的单亚基或双亚基 PFOR 的蛋白质折叠，包括必需的硫胺素焦磷酸（TPP）和三个 [4Fe-4S] 簇的位置。值得注意的是，MaPFOR 通常在 CO 还原方向起作用，并且与丙酮酸氧化 PFOR 的结构比较显示在几个与催化相关的区域存在细微差异。这些研究提供了一个框架，可能有助于阐明促进还原丙酮酸合成所使用的生化机制。
