Hecht H J, Erdmann H, Park H J, Sprinzl M, Schmid R D
Department of Molecular Structure Research, GBF (Gesellschaft fr Biotechnologische, Forschung, Braunschweig, Germany.
Nat Struct Biol. 1995 Dec;2(12):1109-14. doi: 10.1038/nsb1295-1109.
The crystal structures of the flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) containing isoforms of NADH oxidase from Thermus thermophilus have been determined by isomorphous and molecular replacement and refined to 2.3 A and 1.6 A resolution with R-values of 18.5% and 18.6% respectively. The structure of the homodimeric enzyme consists of a central 4-stranded antiparallel beta-sheet covered by helices, a more flexible domain formed by two helices, and a C-terminal excursion connecting the subunits. The active sites are located in a deep cleft between the subunits. The binding site of the flavin cofactor lacks the common nucleotide binding fold and is different from the FMN binding site found in flavodoxins.
嗜热栖热菌中含黄素腺嘌呤二核苷酸（FAD）和黄素单核苷酸（FMN）的NADH氧化酶同工型的晶体结构已通过同晶置换和分子置换法测定，并分别精修至2.3 Å和1.6 Å分辨率，R值分别为18.5%和18.6%。该同二聚体酶的结构由一个被螺旋覆盖的中央4股反平行β折叠、一个由两个螺旋形成的更灵活的结构域以及连接亚基的C端延伸部分组成。活性位点位于亚基之间的深裂隙中。黄素辅因子的结合位点缺乏常见的核苷酸结合折叠，且与黄素氧还蛋白中的FMN结合位点不同。
