2BTN

The Molecular Structure and Catalytic Mechanism of a Quorum-Quenching N-Acyl-L-Homoserine Lactone Hydrolase.

(2005) Proc Natl Acad Sci U S A 102: 17606

• PubMed: 16314577 Search on PubMedSearch on PubMed Central
• DOI: https://doi.org/10.1073/pnas.0504996102
• Primary Citation of Related Structures:  
  2BR6, 2BTN


• PubMed Abstract: 
  

  In many Gram-negative bacteria, including a number of pathogens such as Pseudomonas aeruginosa and Erwinia carotovora, virulence factor production and biofilm formation are linked to the quorum-sensing systems that use diffusible N-acyl-L-homoserine lactones (AHLs) as intercellular messenger molecules. A number of organisms also contain genes coding for lactonases that hydrolyze AHLs into inactive products, thereby blocking the quorum-sensing systems. Consequently, these enzymes attract intense interest for the development of antiinfection therapies. However, the catalytic mechanism of AHL-lactonase is poorly understood and subject to controversy. We here report a 2.0-angstroms resolution structure of the AHL-lactonase from Bacillus thuringiensis and a 1.7-angstroms crystal structure of its complex with L-homoserine lactone. Despite limited sequence similarity, the enzyme shows remarkable structural similarities to glyoxalase II and RNase Z proteins, members of the metallo-beta-lactamase superfamily. We present experimental evidence that AHL-lactonase is a metalloenzyme containing two zinc ions involved in catalysis, and we propose a catalytic mechanism for bacterial metallo-AHL-lactonases.

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Organizational Affiliation: 

Korea Research Institute of Bioscience and Biotechnology, Yusong, Daejon 305-600, Korea.