Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom.
Acta Crystallogr F Struct Biol Commun. 2023 Sep 1;79(Pt 9):224-230. doi: 10.1107/S2053230X23006672. Epub 2023 Aug 15.
The NADPH-dependent imine reductase from Ajellomyces dermatitidis (AdRedAm) catalyzes the reductive amination of certain ketones with amine donors supplied in an equimolar ratio. The structure of AdRedAm has been determined in three forms. The first form, which belongs to space group P321 and was refined to 2.01 Å resolution, features two molecules (one dimer) in the asymmetric unit in complex with the redox-inactive cofactor NADPH. The second form, which belongs to space group C2 and was refined to 1.73 Å resolution, has nine molecules (four and a half dimers) in the asymmetric unit, each complexed with NADP. The third form, which belongs to space group P321 and was refined to 1.52 Å resolution, has one molecule (one half-dimer) in the asymmetric unit. This structure was again complexed with NADP and also with the substrate 2,2-difluoroacetophenone. The different data sets permit the analysis of AdRedAm in different conformational states and also reveal the molecular basis of stereoselectivity in the transformation of fluorinated acetophenone substrates by the enzyme.
青霉菌（Ajellomyces dermatitidis）中的 NADPH 依赖型亚胺还原酶（AdRedAm）能够以等摩尔比的方式，催化某些酮类化合物与胺供体的还原胺化反应。AdRedAm 的结构已通过三种形式确定。第一种形式属于 P321 空间群，其分辨率被精细到 2.01Å，在不对称单元中包含两个分子（一个二聚体），与氧化还原非活性辅因子 NADPH 形成复合物。第二种形式属于 C2 空间群，其分辨率精细到 1.73Å，在不对称单元中包含九个分子（四个半二聚体），每个分子都与 NADP 形成复合物。第三种形式属于 P321 空间群，其分辨率精细到 1.52Å，在不对称单元中仅包含一个分子（一个半二聚体）。该结构再次与 NADP 以及底物 2,2-二氟苯乙酮形成复合物。不同的数据集合允许对 AdRedAm 在不同构象状态下进行分析，也揭示了酶对氟代苯乙酮底物进行立体选择性转化的分子基础。
