Architecture et Fonction des Macromolécules Biologiques (AFMB), Centre National de la Recherche Scientifique (CNRS), Aix-Marseille Université (AMU), UMR 7257, 13288 Marseille, France.
Biodiversité et Biotechnologie Fongiques (BBF), French National Institute for Agriculture, Food, and Environment (INRAE), Aix-Marseille Université (AMU), UMR 1163, 13288 Marseille, France.
Biomolecules. 2021 Nov 4;11(11):1632. doi: 10.3390/biom11111632.
Lytic polysaccharide monooxygenases (LPMOs) are monocopper enzymes secreted by many organisms and viruses. LPMOs catalyze the oxidative cleavage of different types of polysaccharides and are today divided into eight families (AA9-11, AA13-17) within the Auxiliary Activity enzyme class of the CAZy database. LPMOs minimal architecture encompasses a catalytic domain, to which can be appended a carbohydrate-binding module. Intriguingly, we observed that some LPMO sequences also display a C-terminal extension of varying length not associated with any known function or fold. Here, we analyzed 27,060 sequences from different LPMO families and show that 60% have a C-terminal extension predicted to be intrinsically disordered. Our analysis shows that these disordered C-terminal regions (dCTRs) are widespread in all LPMO families (except AA13) and differ in terms of sequence length and amino-acid composition. Noteworthily, these dCTRs have so far only been observed in LPMOs. LPMO-dCTRs share a common polyampholytic nature and an enrichment in serine and threonine residues, suggesting that they undergo post-translational modifications. Interestingly, dCTRs from AA11 and AA15 are enriched in redox-sensitive, conditionally disordered regions. The widespread occurrence of dCTRs in LPMOs from evolutionarily very divergent organisms, hints at a possible functional role and opens new prospects in the field of LPMOs.
溶细胞多糖单加氧酶（LPMOs）是许多生物和病毒分泌的单铜酶。LPMOs 催化不同类型多糖的氧化裂解，目前在 CAZy 数据库的辅助活性酶类中分为八个家族（AA9-11、AA13-17）。LPMO 的最小结构包括一个催化结构域，可在此基础上添加一个碳水化合物结合模块。有趣的是，我们观察到一些 LPMO 序列还显示出长度不等的与任何已知功能或折叠无关的 C 末端延伸。在这里，我们分析了来自不同 LPMO 家族的 27060 个序列，结果表明 60%的序列具有预测为固有无序的 C 末端延伸。我们的分析表明，这些无序的 C 末端区域（dCTRs）广泛存在于所有 LPMO 家族（除 AA13 外）中，在序列长度和氨基酸组成方面存在差异。值得注意的是，这些 dCTRs 迄今为止仅在 LPMO 中观察到。LPMO-dCTRs 具有共同的聚两性电解质性质和丝氨酸和苏氨酸残基的富集，表明它们经历了翻译后修饰。有趣的是，AA11 和 AA15 的 dCTRs 富含氧化还原敏感的、条件无序的区域。在进化上非常不同的生物体的 LPMO 中广泛存在 dCTRs，这暗示了它们可能具有功能作用，并为 LPMO 领域开辟了新的前景。
