Characterization of a Novel N -Acylhomoserine Lactonase RmmL from Ruegeria mobilis YJ3

• Published in: Marine drugs 2018-10, Vol.16 (10), p.370
• Main Authors: Cai, Xiulei, Yu, Min, Shan, Hu, Tian, Xiaorong, Zheng, Yanfen, Xue, Chunxu, Zhang, Xiao-Hua
• Format: Article
• Language: English
• Subjects: Acyl-Butyrolactones - metabolism; Amino Acid Sequence; Amino acid sequences; Amino acids; Aquaculture; Bacteria; Bacterial diseases; Bacterial Infections - microbiology; beta-Lactamases - genetics; beta-Lactamases - metabolism; Biodegradation; Biofilms; Carboxylic Ester Hydrolases - genetics; Carboxylic Ester Hydrolases - metabolism; Cell interactions; Cell signaling; Chemical communication; Chemical compounds; Chromobacterium - drug effects; Cloning; Communication; Communications systems; Conserved sequence; Deactivation; Degradation; DNA; Enzymes; Extracellular; Gene expression; Genomes; Gram-negative bacteria; High performance liquid chromatography; HPLC; Inactivation; Lactones; Lactones - metabolism; Liquid chromatography; Marine crustaceans; Metallography; Microbiological strains; N-acylhomoserine lactonase; Peptides; Pharmacology; Population density; Proteins; Pseudomonas aeruginosa; Pseudomonas aeruginosa - drug effects; Pyocyanin; quorum quenching; Quorum Sensing - genetics; Recombinants; Rhodobacteraceae - genetics; Rhodobacteraceae - metabolism; RmmL; Ruegeria; Ruegeria mobilis; Vibrio - drug effects; Violacein; Virulence; Virulence factors; Virulence Factors - genetics; Virulence Factors - metabolism; Waterborne diseases
• ISSN: 1660-3397; 1660-3397
• DOI: 10.3390/md16100370

Gram-negative bacteria utilize -acylhomoserine lactones (AHLs) as quorum sensing (QS) signaling molecules for intercellular communication. Cell-to-cell communication depends on cell population density, and AHL-dependent QS is related to the production of multiple genes including virulence factors. Quorum quenching (QQ), signal inactivation by enzymatic degradation, is a potential strategy for attenuating QS regulated bacterial infections. Both Gram-positive and -negative bacteria have QQ enzymes that can degrade AHLs. In our previous study, strain YJ3, isolated from healthy shrimp, showed strong AHLs degradative activity. In the current study, an AHL lactonase (designated RmmL) was cloned and characterized from YJ3. Amino acid sequence analysis showed that RmmL has a conserved "HXHXDH" motif and clusters together with lactonase AidC that belongs to the metallo-β-lactamase superfamily. Recombinant RmmL could degrade either short- or long-chain AHLs in vitro. High-performance liquid chromatography analysis indicated that RmmL works as an AHL lactonase catalyzing AHL ring-opening by hydrolyzing lactones. Furthermore, RmmL can reduce the production of pyocyanin by PAO1, while for the violacein and the extracellular protease activities by CV026 and VIB72, no significant reduction was observed. This study suggests that RmmL might be used as a therapeutic agent in aquaculture.