Zhang Zhenyi, Bao Rui, Zhang Yaru, Yu Jiang, Zhou Cong-Zhao, Chen Yuxing
Protein Research Institute, Tongji University, Shanghai 200092, People's Republic of China.
Biochim Biophys Acta. 2009 Jan;1794(1):124-8. doi: 10.1016/j.bbapap.2008.09.011. Epub 2008 Oct 1.
Thioredoxin reductase (TrxR) is a member of the pyridine nucleotide-disulfide oxidoreductase family of the flavoenzymes. It can use a dithiol-disulfide active-site to transfer reducing equivalents from NADPH to thioredoxin (Trx), via the cofactor FAD. In Saccharomyces cerevisiae, the cytoplasmic thioredoxin reductase Trr1 plays an important role in multiple cellular events under the control of transcription factor Yap1 and/or Rho5. Here we present the crystal structure of Trr1 at the resolution of 2.8 A, the first fungal TrxR structure. Structural analysis shows it shares a very similar overall structure to Escherichia coli TrxR. However, fine comparisons indicate some distinct differences at the Trx recognition sites. These differences might be responsible to the species-specific recognition of Trx, which has been demonstrated by previous biochemical assays.
硫氧还蛋白还原酶（TrxR）是黄素酶中吡啶核苷酸 - 二硫化物氧化还原酶家族的成员。它可以利用二硫醇 - 二硫化物活性位点，通过辅因子FAD将还原当量从NADPH转移至硫氧还蛋白（Trx）。在酿酒酵母中，细胞质硫氧还蛋白还原酶Trr1在转录因子Yap1和/或Rho5控制下的多个细胞事件中发挥重要作用。在此，我们展示了分辨率为2.8 Å的Trr1晶体结构，这是首个真菌TrxR结构。结构分析表明，它与大肠杆菌TrxR具有非常相似的整体结构。然而，精细比较显示在Trx识别位点存在一些明显差异。这些差异可能是Trx物种特异性识别的原因，先前的生化分析已证明了这一点。
