Researchers Identify Bactericidal Phospholipase Enzyme from Archaea
Scientists discovered cinquedea, a phospholipase enzyme secreted by the archaeon Haloferax larsenii that kills bacteria by damaging their cell membranes. The enzyme works in nanomolar concentrations against halophilic Pontibacillus bacteria and functions similarly to phospholipases found in hornet venom. This finding suggests archaea could be a valuable source for discovering new antibacterial compounds with diverse mechanisms of action.
Researchers identified cinquedea, a β-hydrolase enzyme secreted by the halophilic archaeon Haloferax larsenii s5a-1, which exhibits potent bactericidal activity against halophilic Pontibacillus bacteria at nanomolar concentrations. The enzyme functions as a phospholipase that damages bacterial cell envelopes by cleaving phosphatidylglycerol, the primary lipid component of the target bacteria's membrane, producing lysophosphatidylglycerol as a cleavage product. The structural similarities between cinquedea and phospholipase A1 from hornet venom suggest convergent evolution of bactericidal mechanisms. This discovery adds to recent findings that archaea encode bactericidal peptidoglycan hydrolases, indicating that archaea employ mechanistically diverse strategies to kill bacteria. The research establishes a framework for identifying and characterizing additional archaeal bactericidal proteins and positions archaea as a promising reservoir for novel antibacterial compound discovery.
What's missing
The study does not discuss potential limitations of the in vitro findings or whether cinquedea's bactericidal activity extends to non-halophilic bacteria or pathogenic species relevant to human medicine. The ecological context for why archaea produce these bactericidal compounds in nature remains unexplored.
What different sources said
- bioRxivCenter
A Bactericidal Phospholipase from Archaea
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