ABSTRACT

Permafrost represents a reservoir for the biodiscovery of cold-adapted proteins which are advantageous in industrial and medical settings. Comparisons between different thermo-adapted proteins can give important information for cold-adaptation bioengineering. We collected permafrost active layer samples from 34 points along a proglacial transect in southwest Greenland. We obtained a deep read coverage assembly (>164x) from nanopore and Illumina sequences for the purposes of i) analysing metagenomic and metatranscriptomic trends of the microbial community of this area, and ii) creating the Cold-Adapted Predicted Protein (CAPP) database. The community showed a similar taxonomic composition in all samples along the transect, with a solid permafrost-shaped community, rather than microbial trends typical of proglacial systems. We retrieved 69 high- and medium-quality metagenome-assembled clusters, 213 complete biosynthetic gene clusters and more than three million predicted proteins. The latter constitute the CAPP database that can provide cold-adapted protein sequence information for protein- and taxon-focused amino acid sequence modifications for the future bioengineering of cold-adapted enzymes. As an example, we focused on the enzyme polyphenol oxidase, and demonstrated how sequence variation information could inform its protein engineering.

中文翻译：

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格陵兰岛永久冻土层活动层的微生物特征和冷适应预测蛋白（CAPP）数据库构建

摘要

永久冻土代表了生物发现冷适应蛋白质的储存库，这在工业和医疗环境中具有优势。不同热适应蛋白之间的比较可以为冷适应生物工程提供重要信息。我们从格陵兰岛西南部冰期横断面沿线的 34 个点收集了永久冻土活动层样本。我们从纳米孔和 Illumina 序列中获得了深度读覆盖组装 (>164x)，目的是 i) 分析该区域微生物群落的宏基因组和宏转录组趋势，以及 ii) 创建冷适应预测蛋白 (CAPP) 数据库。该群落在沿横断面的所有样本中都显示出相似的分类组成，具有坚实的永久冻土形群落，而不是冰期系统典型的微生物趋势。我们检索了 69 个高质量和中等质量的宏基因组组装簇、213 个完整的生物合成基因簇和超过 300 万个预测蛋白质。后者构成了CAPP数据库，可以为未来的冷适应酶生物工程提供以蛋白质和分类单元为重点的氨基酸序列修饰的冷适应蛋白质序列信息。作为一个例子，我们重点关注多酚氧化酶，并演示了序列变异信息如何为其蛋白质工程提供信息。