Abstract

Among the several alcohol dehydrogenases, PQQ-dependent enzymes are mainly found in the α, β, and γ-proteobacteria. These proteins are classified into three main groups. Type I ADHs are localized in the periplasm and contain one Ca²⁺-PQQ moiety, being the methanol dehydrogenase (MDH) the most representative. In recent years, several lanthanide-dependent MDHs have been discovered exploding the understanding of the natural role of lanthanide ions. Type II ADHs are localized in the periplasm and possess one Ca²⁺-PQQ moiety and one heme c group. Finally, type III ADHs are complexes of two or three subunits localized in the cytoplasmic membrane and possess one Ca²⁺-PQQ moiety and four heme c groups, and in one of these proteins, an additional [2Fe-2S] cluster has been discovered recently. From the bioinorganic point of view, PQQ-dependent alcohol dehydrogenases have been revived recently mainly due to the discovery of the lanthanide-dependent enzymes. Here, we review the three types of PQQ-dependent ADHs with special focus on their structural features and electron transfer processes.

Graphic abstract

中文翻译：

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PQQ 依赖性醇脱氢酶的生物无机见解

摘要

在几种醇脱氢酶中，PQQ 依赖性酶主要存在于α、β和γ-变形菌中。这些蛋白质分为三大类。I 型ADH位于周质中，含有一个 Ca ²⁺ -PQQ 部分，甲醇脱氢酶 (MDH) 最具代表性。近年来，已经发现了几种依赖于镧系元素的 MDH，从而使人们对镧系元素离子的自然作用有了深入的了解。II 型ADH位于周质中，具有一个 Ca ²⁺ -PQQ 部分和一个血红素c基团。最后，III 型 ADH 是位于细胞质膜中的两个或三个亚基的复合物，并拥有一个 Ca ²⁺-PQQ 部分和四个血红素c基团，最近在其中一个蛋白质中发现了一个额外的 [2Fe-2S] 簇。从生物无机的角度来看，最近 PQQ 依赖的醇脱氢酶已经复活，主要是由于镧系元素依赖酶的发现。在这里，我们回顾了三种类型的 PQQ 依赖性 ADH，特别关注它们的结构特征和电子转移过程。

图形摘要