Department of Biology, University of Padova, 35131 Padova, Italy.
Biochem Biophys Res Commun. 2011 Feb 25;405(4):678-83. doi: 10.1016/j.bbrc.2011.01.095. Epub 2011 Feb 1.
[FeFe]-hydrogenases have been claimed as the most promising catalysts of hydrogen bioproduction and several efforts have been accomplished to express and purify them. However, previous attemps to obtain a functional recombinant [FeFe]-hydrogenase in heterologous systems such as Escherichia coli failed due to the lack of the specific maturation proteins driving the assembly of its complex active site. The unique exception is that of [FeFe]-hydrogenase from Clostridium pasteurianum that has been expressed in active form in the cyanobacterium Synechococcus PCC 7942, which holds a bidirectional [NiFe]-hydrogenase with a well characterized maturation system, suggesting that the latter is flexible enough to drive the synthesis of a [FeFe]-enzyme. However, the capability of cyanobacteria to correctly fold a [FeFe]-hydrogenase in the absence of its auxiliary maturation proteins is a debated question. In this work, we expressed the [FeFe]-hydrogenase from Chlamydomonas reinhardtii as an active enzyme in the cyanobacterium Synechocystis sp. PCC 6803. Our results, using a different experimental system, confirm that cyanobacteria are able to express a functional [FeFe]-hydrogenase even in the absence of additional chaperones.
[FeFe]-氢化酶被认为是最有前途的氢气生物生产催化剂，已经有多项努力旨在表达和纯化它们。然而，由于缺乏特定的成熟蛋白来驱动其复杂活性位点的组装，以前在大肠杆菌等异源系统中获得功能性重组[FeFe]-氢化酶的尝试都失败了。唯一的例外是产酸克雷伯氏菌的[FeFe]-氢化酶，它以活性形式在集胞藻 PCC 7942 中表达，后者拥有一个双向[NiFe]-氢化酶，其成熟系统特征良好，这表明后者具有足够的灵活性来驱动[FeFe]-酶的合成。然而，在没有辅助成熟蛋白的情况下，蓝藻能否正确折叠[FeFe]-氢化酶是一个有争议的问题。在这项工作中，我们在集胞藻 sp. PCC 6803 中将莱茵衣藻的[FeFe]-氢化酶表达为一种活性酶。我们的结果使用了不同的实验系统，证实了蓝藻即使在没有额外伴侣蛋白的情况下也能够表达功能性[FeFe]-氢化酶。
