Genetic and Structural Diversity of Prokaryotic Ice-Binding Proteins from the Central Arctic Ocean

• Published in: Genes
• Main Authors: Johanna C. Winder, William Boulton, Asaf Salamov, Sarah Lena Eggers, Katja Metfies, Vincent Moulton, Thomas Mock
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2023
• Subjects: metagenomics; MAGs; ice-binding proteins; DUF3494; domain shuffling; polar genomics; Genetics; QH426-470; Arctic; Arctic Ocean; Sea ice
• Online Access: https://doi.org/10.3390/genes14020363; https://doaj.org/article/863dc6104cbc492986d118d588e60fc8

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.