School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
School of Computing Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
Genes (Basel). 2023 Jan 30;14(2):363. doi: 10.3390/genes14020363.
Ice-binding proteins (IBPs) are a group of ecologically and biotechnologically relevant enzymes produced by psychrophilic organisms. Although putative IBPs containing the domain of unknown function (DUF) 3494 have been identified in many taxa of polar microbes, our knowledge of their genetic and structural diversity in natural microbial communities is limited. Here, we used samples from sea ice and sea water collected in the central Arctic Ocean as part of the MOSAiC expedition for metagenome sequencing and the subsequent analyses of metagenome-assembled genomes (MAGs). By linking structurally diverse IBPs to particular environments and potential functions, we reveal that IBP sequences are enriched in interior ice, have diverse genomic contexts and cluster taxonomically. Their diverse protein structures may be a consequence of domain shuffling, leading to variable combinations of protein domains in IBPs and probably reflecting the functional versatility required to thrive in the extreme and variable environment of the central Arctic Ocean.
冰结合蛋白（IBPs）是一组由嗜冷生物产生的具有生态和生物技术相关性的酶。尽管在许多极地微生物的分类群中已经鉴定出含有未知功能域（DUF）3494 的假定 IBPs，但我们对其在自然微生物群落中的遗传和结构多样性的了解是有限的。在这里，我们使用了 MOSAiC 考察队在北极中部海洋采集的海冰和海水样本进行宏基因组测序，并对随后的宏基因组组装基因组（MAGs）进行了分析。通过将结构多样的 IBPs 与特定的环境和潜在的功能联系起来，我们揭示了 IBP 序列在内部冰中富集，具有多样化的基因组背景，并在分类上聚类。它们多样的蛋白质结构可能是结构域改组的结果，导致 IBPs 中蛋白质结构域的可变组合，可能反映了在北极中部海洋这种极端和多变的环境中生存所需的功能多样性。
