A nuclease domain fused to the Snf2 helicase confers antiphage defence in coral‐associated Halomonas meridiana

Autor: Tianlang Liu, Xinyu Gao, Ran Chen, Kaihao Tang, Ziyao Liu, Pengxia Wang, Xiaoxue Wang
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Microbial Biotechnology, Vol 17, Iss 7, Pp n/a-n/a (2024)
Druh dokumentu: article
ISSN: 1751-7915
DOI: 10.1111/1751-7915.14524
Popis: Abstract The coral reef microbiome plays a vital role in the health and resilience of reefs. Previous studies have examined phage therapy for coral pathogens and for modifying the coral reef microbiome, but defence systems against coral‐associated bacteria have received limited attention. Phage defence systems play a crucial role in helping bacteria fight phage infections. In this study, we characterized a new defence system, Hma (HmaA‐HmaB‐HmaC), in the coral‐associated Halomonas meridiana derived from the scleractinian coral Galaxea fascicularis. The Swi2/Snf2 helicase HmaA with a C‐terminal nuclease domain exhibits antiviral activity against Escherichia phage T4. Mutation analysis revealed the nickase activity of the nuclease domain (belonging to PDD/EXK superfamily) of HmaA is essential in phage defence. Additionally, HmaA homologues are present in ~1000 bacterial and archaeal genomes. The high frequency of HmaA helicase in Halomonas strains indicates the widespread presence of these phage defence systems, while the insertion of defence genes in the hma region confirms the existence of a defence gene insertion hotspot. These findings offer insights into the diversity of phage defence systems in coral‐associated bacteria and these diverse defence systems can be further applied into designing probiotics with high‐phage resistance.
Databáze: Directory of Open Access Journals
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