Rhodobacter sphaeroides 偶氮还原酶三级结构同源建模与分析

利用同源建模方法构建了Rhodobacter sphaeroides偶氮还原酶AZR的三级结构模型.结果表明,AZR为α/β型结构的黄素氧化还原蛋白,5个相互平行的β折叠形成分子中间的平面,5个α螺旋分列于平面的两侧;在β折叠的C端非共价结合的黄素单核苷酸(FMN)作为氧化还原反应中心.根据序列对齐分析,将依赖黄素的偶氮还原酶分为两个家族,但结构对比分析表明,它们具有类似的三级结构和活性区域.对AZR的结构研究为发现新的偶氮还原酶和深入研究其功能奠定了基础.

Homology modeling and analysis of three-dimensional structure of azoreductase of Rhodobacter sphaeroides

The three-dimensional structure model of azoreductase AZR of Rhodobacter sphaeroides was constructed using homology modeling method. It is demonstrated that AZR is a flavodoxin adopting α/β structure with the central five-stranded parallel β-sheet flanked by five a helices. A flavin mononucleotide (FMN) prosthetic group lies on top of the molecule, acting as redox and reactive centers. Flavin-dependent azoreductases are classified into two families according to the results of sequence alignments. However, structure analysis indicates that they all possess similar three-dimensional structures and active sites. The study of AZR's structure lays a foundation for finding new azoreductase gene and deeply understanding AZR's function.