School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, China.
Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
BMC Evol Biol. 2019 Mar 13;19(1):76. doi: 10.1186/s12862-019-1394-3.
Unspecific peroxygenases (UPO) (EC 1.11.2.1) represent an intriguing oxidoreductase sub-subclass of heme proteins with peroxygenase and peroxidase activity. With over 300 identified substrates, UPOs catalyze numerous oxidations including 1- or 2- electron oxygenation, selective oxyfunctionalizations, which make them most significant in organic syntheses and potentially attractive as industrial biocatalysts. There are very few UPOs available with distinct properties, notably, MroUPO which shows behavior ranging between UPO and another heme-thiolate peroxidase, called Chloroperoxidase (CPO). It prompted us to search for more UPOs in fungal kingdom which led us to studying their relationship with CPO.
In this study, we searched for novel UPOs in more than 800 fungal genomes and found 113 putative UPO-encoding sequences distributed in 35 different fungal species (or strains), amongst which single sequence per species were subjected to phylogeny study along with CPOs. Our phylogenetic study show that the UPOs are distributed in Basidiomycota and Ascomycota phyla of fungi. The sequence analysis helped to classify the UPOs into five distinct subfamilies: classic AaeUPO and four new subfamilies with potential new traits. We have also shown that each of these five subfamilies (supported by) have their own signature motifs. Surprisingly, some of the CPOs appeared to be a type of UPOs indicating that they were previously identified incorrectly. Selection pressure was observed on important motifs in UPOs which could have driven their functional divergence. Furthermore, the sites having different evolutionary rates caused by the functional divergence were also identified on some motifs along with the other relevant amino acid residues. Finally, we predicted critical amino acids responsible for the functional divergence in the UPOs and identified some sequence differences among UPOs, CPOs, and MroUPO to predict it's ranging behavior.
This study discovers new UPOs, provides a glimpse of their evolution from CPOs, and presents new insight on their functional divergence. We present a new classification of UPOs and shed new light on its phylogenetics. These different UPOs may exhibit a wide range of characteristics and specificities which may help in various fields of synthetic chemistry and industrial biocatalysts, and may as well lead to an advancement towards the understanding of physiological role of UPOs in fungi.
非特异性过氧化物酶（UPO）（EC 1.11.2.1）是血红素蛋白中一个有趣的氧化还原酶亚类，具有过氧化物酶和过氧化物酶活性。UPO 已鉴定出超过 300 种底物，可催化多种氧化反应，包括 1 或 2 电子氧合、选择性氧功能化，这使其在有机合成中具有重要意义，并且作为工业生物催化剂具有潜在吸引力。具有独特性质的 UPO 非常少，值得注意的是，MroUPO 的行为介于 UPO 和另一种血红素硫醇过氧化物酶（称为氯化过氧化物酶（CPO））之间。这促使我们在真菌王国中寻找更多的 UPO，从而导致我们研究它们与 CPO 的关系。
在这项研究中，我们在 800 多个真菌基因组中搜索了新的 UPO，并在 35 种不同的真菌物种（或菌株）中发现了 113 个推定的 UPO 编码序列，其中每个物种的单个序列都进行了系统发育研究与 CPO 一起。我们的系统发育研究表明，UPO 分布在担子菌门和子囊菌门真菌中。序列分析有助于将 UPO 分为五个不同的亚科：经典的 AaeUPO 和四个具有潜在新特征的新亚科。我们还表明，这五个亚科中的每一个（由）都有自己的特征基序。令人惊讶的是，一些 CPO 似乎是 UPO 的一种类型，表明它们以前的鉴定不正确。在 UPO 中观察到重要基序的选择压力，这可能导致了它们的功能分化。此外，还确定了一些基序上由于功能分化而导致进化速率不同的位点，以及其他相关氨基酸残基。最后，我们预测了 UPO 功能分化的关键氨基酸，并确定了 UPO、CPO 和 MroUPO 之间的一些序列差异，以预测其行为范围。
本研究发现了新的 UPO，提供了它们从 CPO 进化的视角，并对它们的功能分化提出了新的见解。我们提出了 UPO 的新分类，并对其系统发生学进行了新的阐述。这些不同的 UPO 可能表现出广泛的特征和特异性，这可能有助于合成化学和工业生物催化剂的各个领域，并可能有助于深入了解 UPO 在真菌中的生理作用。
